Ford P0401 Code Scanned – Expedition 4.6 EGR Low Flow

9:42 pm DIY, Ford Problems, How To Auto Repair

 

Ford_Expedition_P0401

2000 Ford Expedition P0401 doesn’t necessarily mean the EGR is bad

Summary: Ford DPFE problems discussed. Common causes for Ford EGR low flow issues and P0401 fault code triggered. Don’t replace the EGR (Exhaust Gas Recirculation) valve just yet if you have a P0401 code on a 4.6 liter engine like the one in this Expedition. The diagnostic code definition states “Low flow from E.G.R.” Low flow doesn’t mean definitively that the EGR is bad. Low EGR flow can be a problem in any Ford, Mercury, Lincoln, Mazda and many other car’s for that matter. On a lot of Ford vehicles this code will mean there is a faulty Differential or Delta Pressure Feedback (DPFE) sensor. This was such a common problem there was an extended warranty coverage on them for awhile. Not many people knew about Ford covering these on some models for an extended period of time. At the shop I worked at, an extended warranty company first alerted us to this when they declined an extended warranty claim because Ford would replace it under warranty.

DPFE

What is a DPFE and what does it do?

The DPFE helps the vehicle’s computer to insure that the EGR (Exhaust Gas Recirculation) system is working properly. The sensor monitors the exhaust pressure in the exhaust, usually from a passage in the vehicle’s intake. The sensor sends a reading to the vehicle’s computer. If the expected changes in pressure are not seen by the PCM (Power Train Control Module) the CEL (Check Engine Light) will be turned on. Most of the time performance issues aren’t noticeable. Sometimes pinging upon acceleration can be detected if the DPFE is not working properly. It is usually located near the EGR, in fact some late model Ford’s have the DPFE built right into the EGR. The sensor is prone to failure mainly because of the harsh exhaust it is exposed to. Between carbon build up and corrosion, a bad DPFE is a common problem. On the 2000 Ford Expedition, the original DPFE was aluminum… it doesn’t rust! The problem is that aluminum does corrode. The replacement DPFE is made of plastic, which is an improved design but failures of these are still fairly common.

Ford_Expedition_P0401_C

With throttle body removed and mirror in place the passages can be seen

Ford_Expedition_P0401_B

The two dark spots are two badly restricted EGR passages

EGR Passages

The passages on the Expedition in the picture above are shown with the throttle removed. They are obviously restricted, completely blocked off with carbon build up. The passages go down, then to the right where they meet with the EGR. With the EGR removed, the passages can be cleaned out with fuel injection spray cleaner, a spare coat hanger and a thin bottle brush from the kitchen. Compressed air helps blow through the gunk and clear the passages, allowing the EGR, DPFE and PCM to work together.

  • Vacuum can be applied to an EGR with a hand vacuum pump, while it’s running to see if the idle drops. Sometimes the idle can drop some but the passages may still be partially clogged.
  • When replacing a DPFE sensor, if there are rubber hoses, blow through them with compressed air to clean out any loose debris.
  • Replace DPFE hoses that have excessive deterioration. Regular hoses won’t work, it takes special DPFE sensor hoses to withstand the high temperatures.
  • Try cleaning the EGR passages first to attempt to save money. Replace the DPFE sensor if the diagnostic code returns.
  • Don’t buy a used one, this is such a common problem chances are not good to find a good one in a salvage yard.
  • The diaphragm in the EGR can leak but it’s not as common as the above mentioned problems.
146 Responses
  1. robert :

    Date: February 27, 2010 @ 10:21 pm

    I hope you can help me. It’s just driving me crazy. I have a 2001 Hyundai Santa fe GL 4 cyclinder that I am giving my sixteen year old as his first car. It is in perfect condition but the check engine lite has been on for three years. I have now found the time to tacklce this so I bought a code reader and the code comes up with P0171 TO LEAN BANK 1. I looked on the internet and it seems to be pointing towards the mass flow sensor. I purchased mass flow sensor cleaner took it apart and cleaned it good. For about three days no engine lite but during a rainy day it turned back on. I cleaned it again and reset the lite and I am seeing if it comes on again but it will probably turn on in a few days. What else could it be.-Thank You

  2. dennisb - Auto Tool Sales :

    Date: February 28, 2010 @ 8:31 pm

    Robert, you may want to see our blog on Lean Codes.

  3. Dan Smith :

    Date: March 2, 2010 @ 8:14 pm

    - I cant say my problem will be resolved with the information here, but I want to say a huge thanks for posting this to the web because this is what the web should be.
    - I wouldn’t mind taking my truck in for this problem, which matches what is described here, but dealerships now have such a horrible reputation. I have worked in them before and I really believe some are the worst they’ve ever been.

  4. dennisb - Auto Tool Sales :

    Date: March 2, 2010 @ 9:37 pm

    Dan, If you have a similar vehicle with the same code, then you have a very good chance of repairing the problem with the information in this auto repair blog.

    Car dealers are like doctors, there’s good ones and bad ones. Also, if this is something you don’t feel like handling yourself, you could print this page and go in to the dealer armed with information. You are less likely to be taken advantage of if you are knowledgeable of the repair.

  5. john :

    Date: March 4, 2010 @ 8:38 pm

    I have a 2001 Expo 4.6. I am getting the p0401 code and i have a reader. I have replaced the egr, erg selonoid and the dpfe. I failed smog after I cleared the code becuase it didnt go through a whole drive cycle. When I was taking off the old dpfe which was metal I noticed that there was two metal pipe that went downwards but there was no rubber hoses attached to them. I replaced it with the new plastic dpfe but I cannot find any hoses that go to the EGR. Does the 4.6 not have rubber hoses attached to the dpfe, or did they just burn up because I cant find them anywhere on the car. My friend who has a f150 5.8 has hoses attached to them. Could this be causing my CEL-Please Help this is driving me crazy and have 18 more days to pass smog!!!!!!!!!

  6. steve t. :

    Date: March 11, 2010 @ 11:12 am

    yes John,,,,,,that is your prob. hit the parts store or dealer near you and tell them you need the hoses ,, they are made for vey hi -temp ,, get the right 1′s or you’ll be right back where you started!!!!

  7. zac bolin :

    Date: May 20, 2010 @ 9:34 pm

    yes i just figured this one out on a friends 2000 ford expedition an dit worked but one thing the parts are all new. will it hurt to replace all the o2 sensors as well as the egr pressure valve and the acuator solenoid and the egr flow module and clean everything out? i have also noticed that when all these are done the gas milage is a major differnce. its a whole lot better. will it hurt to put the new e3 dual fire spark plugs in the ford expidition with premium fuel to get even better gas milage on this truck?

  8. Ken H :

    Date: June 19, 2010 @ 8:54 pm

    2001 expedition,have p0401,found white vac line laying on intake manifold, dpfe has been removed by unknown. had both head valve job about 2 years ago by dealer. not sure which way to go. back to dealer or try myself.

  9. dennisb - Auto Tool Sales :

    Date: June 20, 2010 @ 7:50 am

    Ken, the DPFE being removed should have caused a check engine light to come on. A white vacuum line definitely is NOT for the DPFE (DPFE hoses are black). Need to find vacuum hose routing in a repair manual – see our on-line repair manual information linked at the top. You might also want to ask a Ford dealer tech for help by visiting our Car Questions page linked at the top as well. Paying for a few questions to be answered is cheaper than paying shop labor rates, if you are able to do a little work yourself to get things back in order.

  10. Ken H :

    Date: June 22, 2010 @ 1:50 pm

    Update: the white vacuum line was off the vapor management valve, it must have been off since the valve job because it was laying on top of the intake manifold. The DPFE sensor is located nearer to the firewall; it is a tube mounted type, instead of bolt on as I thought. I took your advice and subscribed to Mitchell diy. It was very helpful. Again I thank you very much dennisb.

  11. dennisb - Auto Tool Sales :

    Date: June 22, 2010 @ 3:27 pm

    Ken H, Alright that’s great. You gotta luv when a plan comes together ;)

  12. Joe Miller :

    Date: June 23, 2010 @ 10:48 pm

    I’ve had this problem for a few years and after replacing DPFE and EGR valve as well as cleaning all [or so I thought] pipes, hoses, and passages to the EGR, I still had the issue up until today when I saw your throttle body illustration. I knew that was it right away. I removed the throttle body to thoroughly clean the completely blocked passages. I used a pick and a couple of different sizes of gun bore brushes. They worked great and it now runs fantastic! Bless you sir! [Side note, this carbon build-up is due to my lack of immediate attention when my Motorcraft coils faulted one at a time.] Great article! Thanks again!

  13. dennisb - Auto Tool Sales :

    Date: June 24, 2010 @ 6:17 am

    Joe, I appreciate you letting us know how your repair went. Glad this article helped. Don’t be surprised if the carbon builds up again over time even with no misfiring coils. At least you will know where to look.

    I first learned about the EGR passages on this particular model being prone to clog, years ago when I worked with a Ford master technician (Ed Candelaria) in Tampa Florida. It’s one of those things that would be hard to figure out, without some insight from someone that has had dealership experience. Thanks Ed!

  14. Ken H :

    Date: August 6, 2010 @ 6:00 pm

    Hi Dennis, I’m noticing another problem w/my 01 expedition. when it starts up cold, engine idles and runs rough until engine heats up, it’s not severe,and it’s good as long as it doesn’t cool down again but seems to be getting a little worse. Not sure how to start looking at this one, no service soon light.
    thanks, Ken H.

  15. dennisb - Auto Tool Sales :

    Date: August 8, 2010 @ 8:12 am

    Ken, could be just a dirty throttle body or IAC (Idle Air Control) valve. Another possibility is spark plug wires if it is a misfire and not just a little rough idle. Mode 6 accessed with a scan tool may help to see a misfire count BEFORE a P300 series code sets. See the article linked below. The easiest thing to try first is a throttle body cleaning though.

    MODE 6 Misfires

  16. Scott C. :

    Date: October 4, 2010 @ 8:46 pm

    Does the P0405 code have to do with the P0401? Also when I start the vehicle once every 4 or 5 starts it will puff a huge white smoke cloud. Is this part of the DPFE problem?

  17. dennisb :

    Date: October 5, 2010 @ 10:02 am

    Scott, the most likely cause is a bad DPFE. Inspect the hoses and replace as necessary also.

    Another not so common issue may be restricted catalytic converters causing the DPFE to overheat and malfunction – so if you have the plastic type look for signs of over-heating, like melting.

    As far as the white smoke issue probably unrelated. Usually because of water in the exhaust steaming out. Could be normal if just condensation as long as it’s not an extreme amount. If coolant loss is also occuring, suspect a leaky head gasket and do further testing.

  18. John J. :

    Date: October 15, 2010 @ 11:29 am

    I just wanted to say thanks. I’ve been trying to pass emissions with the P0401 code. I replaced DPFE and EGR valve and cleaned out the EGR tube. But still had a problem, that was until I saw this forum. As soon as I saw your pics of the plugged ports in the intake I knew that was it. Although I had to take the section behind the throttle body off to get the carbon build up out with a screwdriver, it worked great. Then some carb cleaner and a tube brush cleaned it right up.
    Thanks again.

  19. Andi :

    Date: October 21, 2010 @ 1:53 pm

    I have a Ford expedition 4.6 and continue to get a P401 code. I have replaced the EGR manifold, sensor and DPFE sensor. I also had an intake cleaner with ISC with the machine done and still continue to get the same code. I also around 40 – 45 miles per hour have a spark detonation when shifting. The only thing I can imagine is when changing the first manifold the first time the brake booster bracket broke, but the people over at Auto Zone said not a problem put tape around the hole it was only for stablelation. Is this correct? Can you think of what else could be the cause of the P401 code? I have changed all the EGR parts (manifold, sensor & DPFE numerous times with no avail) The trucks starts but I can’t seems to find the answer to this darn code.
    Much Thanks

  20. dennisb - Auto Tool Sales :

    Date: October 21, 2010 @ 2:32 pm

    Andi, I would look for plugged or restrcited EGR ports. Just simply running intake or FI cleaner will NOT clean the ports. The brake booster bracket should have no affect on EGR performance.

  21. Andi :

    Date: October 21, 2010 @ 5:01 pm

    Thank you for the prompt response! May I ask what do you suggest to clean the ports with?
    Much Thanks
    Andi

  22. dennisb - Auto Tool Sales :

    Date: October 22, 2010 @ 6:44 am

    Andi, below is the part from the article that pertains your question. Passages or ports are the same.

    “With the EGR removed, the passages can be cleaned out with fuel injection spray cleaner, a spare coat hanger and a thin bottle brush from the kitchen. Compressed air helps blow through the gunk and clear the passages”

  23. Andi :

    Date: October 25, 2010 @ 10:48 am

    Gosh, I hate to baragh you with so many question but I feel you’re my best best with getting an honest answer. I feel like a fish out of water with the owner at the mechanic place being a woman. The day of my post I took my car over to the shop and they took all three parts off and had replaced them with all new onces again from Auto Zone. They put compressed air into all the tubes and I could hear the air going through. They didn’t use any cleaners though that I could see. My manifold has the two screws on the outside and one big hole in the middle and this is where the EGR manifold attaches too. The middle hole is just smaller then my thumb. is this the intake? If so, Is this where I would put intake cleaner? while the enigine is ideling or not ideling? from a visual perspective no carbon build up is there. The exhaust tube that attaches to the muffler in the far back was scrapped and the mechanic said their was no appearant carbon build up there. since putting on the new three parts my MPG has dropped again. I would love to find the cause of the code so I can ease undue stress on the engine.
    Thank you sooo much once again,
    Andi

  24. Reg :

    Date: November 24, 2010 @ 6:38 pm

    That is my exact problem. My wife’s 2000 Expedition, 4.6, has been reading that same P0401 for a while now. Doing some research online I noticed that the DPFE was a reoccuring theme. I replaced the DPFE and had the carbon cleaning “done” by a service shop. Recently the code came back so I did what testing Haynes says to do and I finally changed the EGR Valve as well, even though many said it rarely fails. (makes the wife feel better knowing I replaced rather than cleaned). Now the code returned again!!!!! I wish I read your post sooner, I’m headed out to the garage to do what you said. Many thanks for the assist and I’ll definitely report when complete.

  25. Mark :

    Date: November 27, 2010 @ 1:23 am

    I have been having the same 0401 code on my 97 exp, can the procedures that have been described for the 01′ with the EGR passages? and is the fix the same? are the EGR passages part of the throttle body or the EGR valve? Help

  26. dennisb - Auto Tool Sales :

    Date: November 27, 2010 @ 8:13 am

    Mark, I believe that the throttle body, intake and EGR are all the same on 1997, 1998, 1999, 2000, 2001 and 2002 with 4.6 Liter engines. We used to get a lot of Crown Victorias with the same set-up also. The passages are in the upper intake (remove the t-body and look with mirror). The passages are NOT part of the EGR, they go to it though.

    When you remove the throttle body and look with a mirror as shown in the images you will know for sure. Remove the EGR, when cleaning – it is removed in the 1st image with the mirror. It’s not just a matter of spraying FI cleaner through the throttle body or paying a shop to do a fuel injection service. The build-up is too tough for any of that to work. I’ve also seen guys in the shop clean the passages, but NOT thoroughly enough. If you clean only one side and not the other the “insufficient flow” code will return. Good Luck.

  27. Mark :

    Date: November 28, 2010 @ 1:13 pm

    Would have continued to replace part after part or spending a fortune at a dealer. the ports were completely blocked, cleaned them out, and reset the code. Looks good so far. Thank you very much.

  28. Richard :

    Date: January 13, 2011 @ 4:12 pm

    My 1999 Ford Expedition (4.6L) runs rough when I first start it up. After it warms up it runs fine. The Service Engine Soon light (CEL) has come on and stays on.

    I had Autozone read the diagnostic codes for me and it came out as P0303
    (misfire detected-cylinder number 3).

    I took the vacuum line off of the EGR Valve and plugged the vaccum line. It now runs just fine when the engine is first started and when it warms up.

    Is this mode of operation harmful to the vehicle, will it hurt gas mileage?

    I replaced the DPFE and had the ports cleaned about 10 months ago when I had a similar problem and this seemed to fix the problem until now. Do you think I should clean the EGR ports and/or replace the DPFE again?
    Richard

  29. dennisb - Auto Tool Sales :

    Date: January 13, 2011 @ 8:22 pm

    Richard, you correctly stated P0303 is a misfire code for the #3 cylinder. If the CEL flashes this is an indication that there’s a severe enough misfire, which could damage the catalytic converter.

    I would address the P0303 misfire code which has nothing to do with the P0401 EGR low flow code. Low flow of EGR P0401 will NOT cause a misfire code, especially on ONE cylinder.
    Common causes for misfire codes like the P0303 could be a spark plug, spark plug wire or boot, a coil or an injector. Less common problems could be from a mechanical problem with a valve or piston ring etc.

    If the vacuum line remains plugged off, there will likely be a fault code set due to that.

    For best gas mileage I would concentrate on the misfire issue. I would not look for problems with the EGR, plugged ports or bad DPFE unless there’s a corresponding (related) code.
    Good Luck!

  30. Wil :

    Date: January 17, 2011 @ 9:40 pm

    I was removing the screw holding the egr vavle when the screw broke!! What now, how do I remove the broken screw and continue with the work, HELP…..

  31. Gc :

    Date: January 21, 2011 @ 12:25 am

    I just pulled a p0401 code out of my 98 Expedition (Thanks autozone). with his blog, im glad i didn’t go to a mechanic first. I might attempt the fix. thanks guys

  32. Aaron :

    Date: January 24, 2011 @ 8:01 pm

    WOW, thanks Dennis, I have been trying to fix this code for the last month. Cleaned the throttle body, replced EGR, etc. I did know there were these two little holes going to the EGR valve. After all that a can of Seafoam,coat hanger and a wire brush. DONE NO more code and I am passing smog like a champ.

  33. Gc :

    Date: January 28, 2011 @ 11:46 am

    Hi Dennis. So I am attempting to fix p0401, p0171 and p0174 on 98 expedition 4.6l Windsor. So far I cleaned MAF sensor, changed the PCV valve and checked for air leaks. My next suspect is the DPFE, which when I disconnect while the truck is running, no change in idle at all (I don’t know if this is normal) and I will clean the passages as well. Am I on the right track, considering I have 3 codes not just p0401? Also I should mention that there is a white creamy substance on oil cap but the engine block looks free of water. After changing the pcv valve, car runs better but still hesitates when accelerating and I can hear valves clicking. Thanks Dennis.

  34. dennisb - Auto Tool Sales :

    Date: January 28, 2011 @ 1:28 pm

    Sounds like several problems. Be sure to check out our articles on lean codes as well for the P0171 and P0174. Creamy substance could be just condesation mixing with oil. NONE of the codes you mentioned would cause valve noise (maybe lifters). Hesistation could be tune up related or possibly a TPS issue. Good Luck

  35. Gc :

    Date: January 28, 2011 @ 4:45 pm

    Thank you Dennis. I will read up more about lean codes, which seems now a separate issue from p0401.

  36. Gc :

    Date: February 6, 2011 @ 6:54 pm

    Reporting back. Took the throttle body and spacer out and cleaned completely blocked passages, the egr valve is now working :)

  37. dennisb - Auto Tool Sales :

    Date: February 6, 2011 @ 7:22 pm

    Well done. Just in time to watch the big game!

  38. Tim :

    Date: February 8, 2011 @ 8:44 pm

    I have a 1999 Expedition that when I start it when it is cold runs and idles rough. It has even died on me. Warms up goes away. It does have the EGR valve code and bank one and two sensors codes. There is no miss fire code. I have replaced my EGR valve and am fixing to replace the DPFE sensor. Any thoughts?

  39. dennisb - Auto Tool Sales :

    Date: February 8, 2011 @ 9:45 pm

    Tim,

    If I was working on it I would clean the EGR ports and throttle plates. Also the IAC (Idle Air Control) motor since that can affect idle too. I would then recheck and see if the problem is taken care of. Good Luck

  40. Joe :

    Date: February 12, 2011 @ 10:37 pm

    Hey Ive been having the same codes and the same probs on my 97 ford expedition, thanks for the advice im going out tomorrow morning to clean the ports. Could that be the same prob with my 96 ford taurus i replaced the egr valve and more and the check engine light went out long enough for me to pass testing but it will come on for about a week the go out for a couple then back on. thanks

  41. dennisb - Auto Tool Sales :

    Date: February 13, 2011 @ 6:53 am

    Joe, the most common issue on the 1996 Taurus 3.0 Liter a bad DPFE valve (also check DPFE hoses). However it is possible that the passages are closed with carbon build up.

    Here’s How to Check for a Blocked Passage Issue

    If you are still getting trouble codes P0401 (Low Flow) and P1408 (EGR Self Test out of Range). And you have already replaced the Differential Pressure Feedback EGR (DPFE) and the Exhaust Gas Recirculation (EGR) valve.
    Try using a hand held vacuum pump to make the EGR open with the engine running at idle. The car’s motor should have a very rough idle with vacuum applied.

    If the engine’s idle does not change and run rough as expected, the problem is most likely a plugged or restricted EGR passage in the intake manifold. To remove the carbon, remove the throttle body (similar job as in this repair article). And clean the carbon deposits from the passage in the intake. After the ports are clear, the vacuum test can be performed again to recheck.

  42. Joe :

    Date: February 13, 2011 @ 6:25 pm

    Wow is all I can say. On the Expedition I didn’t even have to use a mirror I could see the deposits sticking out, on the Taurus I couldnt even see the passages. You are a life and paycheck saver.

  43. dennisb - Auto Tool Sales :

    Date: February 13, 2011 @ 8:41 pm

    Sweet! Glad I could help.

  44. Alex H :

    Date: March 20, 2011 @ 8:33 pm

    Tim,

    First of all, thumbs up for your knowledge, respect.
    I have a 1998 5.4 EB, first had the P0401 code. I cleaned the two ports of the DPFE, one was clogged and replaced the hoses. Erased the codes, run and idle rough and now P1401 came in. I removed the hoses, connector and the car would still idle rough, no difference noticed. My guess DPFE, yours??
    Have new cop’s, plugs, fuel filter, pcv.

    thanks

    Alex ( Dutch antilles where the have almost nothing on stock :(

  45. dennisb - Auto Tool Sales :

    Date: March 21, 2011 @ 8:32 am

    Tim,

    DPFE’s are a very common failure. Good Luck

  46. Alex H :

    Date: March 21, 2011 @ 4:21 pm

    Dennis, sorry, used the wrond name.

    This was for you.
    First of all, thumbs up for your knowledge, respect.
    I have a 1998 5.4 EB, first had the P0401 code. I cleaned the two ports of the DPFE, one was clogged and replaced the hoses. Erased the codes, run and idle rough and now P1401 came in. I removed the hoses, connector and the car would still idle rough, no difference noticed. My guess DPFE, yours??
    Have new cop’s, plugs, fuel filter, pcv.

    thanks

    Alex ( Dutch antilles where the have almost nothing on stock

  47. jose m. :

    Date: June 27, 2011 @ 9:26 pm

    have a 2001 ford f150 4.2 v6 and my problem is that when my engine warms up and it’s above 75f degrees and I’m at idle, it goes below idle then back up (around 650rpms)often, but not always. no check engine light on. checked vacuum lines,look ok. any suggestions.

  48. dennisb - Auto Tool Sales :

    Date: June 28, 2011 @ 6:53 am

    Jose, a common problem is a collapsed vacuum hose or 90 degree rubber elbow. The collapsed hose would not cause a lean code (& ck eng. light) but could effect the idle. At different temps, there could be a variance in how “collapsed” the hose is. Another possibility would be the IAC (Idle Air Control) Valve/Motor. We have articles here on this site about lean codes which may provide more information. Good Luck.

  49. K V :

    Date: September 25, 2011 @ 8:40 pm

    Hi 99 ford expedition. PO401 code (low flow egr) an have replaced dpfe sensor, checked ports, and valve holds vacuum while running. Not sure what else it could be. Any tips?

    Thanks!

  50. dennisb - Auto Tool Sales :

    Date: September 26, 2011 @ 6:14 am

    KV, If I were working on it I would clean the ports. A 1999 with the design above undoubtedly has build up. Good Luck.

  51. Tony M. :

    Date: October 20, 2011 @ 10:42 pm

    Dennis I own a 2003 Expedition, with codes p0405, p0171, I was told it a short on a dpfe sensor, also the right side hose (high side) coming out of the dpfe was out, I plugged back in but when I accelerate it comes back of. I replaced the dpfe with a oem, same problem lost hose and light back on. I dont seem to have any loss of power, not sure if cat is clogged…….what do you think O2 sensor, egr valve? please help!!

  52. dennisb - Auto Tool Sales :

    Date: October 21, 2011 @ 6:24 am

    Tony, the 2003 you have is a different design than the one in the article. If the hose is in good condition and not just falling off there could be too much exhaust back pressure. I have never seen or heard of that problem (hosed popping off) so you may want to check with a Ford tech for advice. Good Luck.

  53. justin k :

    Date: October 22, 2011 @ 1:30 am

    hi dennis i have a 2000 expy 4.6 i have the po401 but i have also noticed my engine idles real low and then real high when both in gear and just sitting at idle with no other codes please help just bought the truck and want to fix it

  54. dennisb - Auto Tool Sales :

    Date: October 22, 2011 @ 7:57 am

    Justin, I would fix the EGR issue and see if the problem remains. Vacuum leaks and IAC (Idle Air Control) motors can cause idle issues. But, if the engine does not shut off, fluctuation of idle may be normal (600 RPMS to 900 RPMS). It’s normal for idle changes with the AC cycling on and off and when there are other varying load and electrical demands. Good Luck.

  55. Oz :

    Date: October 24, 2011 @ 3:07 pm

    We just traded out ’02 Dodge Grand Caravan Sport in for an ’01 Ford Expedition. I just “love” driving the thing. I looove the power. However, I do have the same problem as above, so I’ll start with cleaning the passages. My question is how do I remove the throtlle. The picture above says “with the throttle removed”. Could you please tell me how I remove the throttle?
    Thanks,

  56. dennisb - Auto Tool Sales :

    Date: October 24, 2011 @ 8:03 pm

    Oz, very easy if you have minimal mechanical experience (4 nuts & a throttle cable). No offense but if you have to ask this may be out of your skill level. Good Luck.

  57. Oz :

    Date: November 1, 2011 @ 11:23 am

    I just asked too fast. Sorry. I cleaning the throttle body out over the weekend, to see if it’ll clear the light. I’ll probably end up[ cleaning the passages as described above. Here is my question. At what point you decided to replace the valve? Assume I cleaned the passages and put everything back together. If I give the valve a little squezee underneath and the car still doesn’t choke, is that when you say “ok. The valve is bad”?

  58. Oz :

    Date: November 1, 2011 @ 11:23 am

    Sorry, I meant I cleaned the throttle body over the weekend.

  59. Cody :

    Date: November 21, 2011 @ 7:23 pm

    I just received a 2001 expedition and will not pass insection due to the infamous P0401 code. I Replaced the EGR valve and DPFE sensor, also cleaned out that hole into the engine block when the valve is off with carb cleaner. Still have P0401 code and no hair left to pull.

  60. dennisb - Auto Tool Sales :

    Date: November 21, 2011 @ 7:59 pm

    Cody carb cleaner alone is not going to clear out those plugged ports in the intake behind the throttle body. Note there are TWO of them (see the image that has the mirror). If BOTH are not cleaned out completely with a wire or something similar, the code will keep coming back. Good Luck.

  61. Ron :

    Date: November 26, 2011 @ 12:18 am

    Does anyone know how to fix a high idle on a 1997 ford expedition xlt 4.6l 4×4 w series replaced intake control sensor , PVC valve already

  62. Ed :

    Date: January 2, 2012 @ 10:16 pm

    Wow! very helpful article. 2000 Expedition was throwing the 401 code and sure enough, those ports were so clogged, they actually had built up a small mound beyond the surface of port! Prior to the code I was having a problem where the vehicle would idle fine with the trans in park (whether hot or cold) but would want to stall out if I was at a stop with the car in drive. Not sure if that was related but it seems better already now that those pesky ports are cleaned. THANK YOU!

  63. dennisb - Auto Tool Sales :

    Date: January 3, 2012 @ 6:52 am

    Ed, glad the information here helped. Keep us in mind for your automotive specialty tools in the future. Happy New Year!

    Auto Tools

  64. Tara :

    Date: April 9, 2012 @ 10:36 am

    Need help my 01 expedtion has been fine until recently and always had the cel on, well later on it started idle jumping and hesitation the computer codes said bank one lean 1 bank 1 lean 2 both auto stores said oxygen sensors. 1 down stream 1 upstream changed both the jumping idle stopped almost instantly and gas mileage doubled but hesitated in idle still there when in idle and a week or two ago I was going down the road and it just stopped on me the motor stayed running but it was like it wasn’t getting any gas. So I pulled over tried to start it back was already started just not going, so turned it off. Started it up it would start idle goes up then dies instantly every-time. Sometimes I could get it to move an inch or so while holding the gas but thats it. Then dies immediately even holding gas down while starting idle goes way up then dies immediately. Took to my mechanic and he couldn’t figure it out either computer keeps saying the same thing we changed p0171 I think o2 sensors but we changed them and he got in and tried to start it by holding gas half way down and it finally started and been running ever since. But now im noticing when I go to start the car you can hear like a click clikc noise maybe a relay? We think it could be idle sensor or main relay but not sure about anything at this point and don’t want to just keep spending money when nothings for sure and it still does the idle hesitation.. please help and thank you.

  65. dennisb - Auto Tool Sales :

    Date: April 9, 2012 @ 11:00 am

    Tara, this article is on the EGR low flow problem with a P0401. Sounds like you may need a lot more guidance than I can provide here. You may want to ask your question to a Ford tech on our questions page. They can help you pinpoint your issue with the lean code, hesitation and poor idle. Good Luck

  66. scott :

    Date: May 26, 2012 @ 3:24 pm

    I have an 01′ Ford Experdition I took it to Auto Zone so they could read me out the code. Three codes came up. One was the Mass Air Flow changed it that’s the main one. The second one was the erg sensor and the third one is heated oxgen sensor bank 2. truck is driving ruff still. I thougth maybe if I change the maf sensor it will drive better …..was the next step

  67. Jim T :

    Date: June 19, 2012 @ 4:01 pm

    I have a 98 ford Expedition 4.6L. It was running fine then one morning it would not start, but it is turning over fine. I can hear the fuel pump running. The codes are P0401, P0420, P0442, P0430 and P0174. Does anyone know what I can try next. Thanks

  68. dennisb - Auto Tool Sales :

    Date: June 19, 2012 @ 5:10 pm

    Jim, you also need enough pressure from the fuel pump and injector pulse. I would try a little starting fluid first. If it wants to start you know it’s not spark related. If it doesn’t sound like it’s trying to start (with starting fluid) I would check scan tool data for RPM’s. No Rpm’s might indicate a bad crank sensor. A bad crank sensor would cause no fuel injector pulse. Good Luck.

  69. Eric :

    Date: July 12, 2012 @ 11:17 pm

    dennisb,
    I dub you the answer man. First of all thanks to people like you, driveway mechs. like my self get some great info.
    Got one for you, I have a 03 Expedition Eddie Bauer 4X4. Wife drives the car on daily basis and has had the car stall out while driving 10-20-…80mph and in the driveway, cooling it down with A/C, cranking before her run to work. Climbed under the hood and removed and cleaned the air intake valve, inspected all hoses and found a torn rear hose coming off the DPFE sensor and found the fitting to the sensor on that hose was not so snug. I put a small clamp on that fitting and has seemed to have solved it. No CEL. Expy seems to not be stalling out but noticing spiratic flutuations in fuel consumption. Idling at 6-900 RPM’s. At this point, I am going to replace the hose and most likely the sensor and just move forward with the clean out of the EGR valve, throttle body etc. Am I wastin’ time or movin in the right direction?
    Bottom line wife refuses to drive vehicle till fixed 100%. Told her we could swap and she can drive my 83 CJ7…haha! Doesnt like that answer. Thanks for your time man, your bucket of karma must be overflowin.

  70. dennisb - Auto Tool Sales :

    Date: July 13, 2012 @ 7:57 am

    Eric, thanks for your comments. Since there’s no CEL (Check Engine Light) on, I wouldn’t be overly concerned about the DPFE. Even if there was a code for it, I’ve never heard of stalling being the cause of a bad DPFE, it could cause spark knock on acceleration.

    For the stalling issue, I would suspect the IAC (Idle Air Control) solenoid was sticking. And that would make sense because after you cleaned it, there was no more stalling. If the problem returns I would replace it. Unless I had a fault code, I wouldn’t worry with cleaning the EGR ports. I would however, clean the throttle plates and make sure the air filter is clean.

    As you know, fuel mileage can vary greatly depending on how the vehicle is driven, how much air is in the tires, how long the it sits idling… etc. I would make sure the tires are aired up, maybe pull a spark plug and see if they are worn (change them if they need it). And watch how long I leave the vehicle running in the driveway. Of course there’s only so much you can do to increase the gas mileage on this type of vehicle. Good Luck.

  71. rocket ryan :

    Date: July 20, 2012 @ 9:58 pm

    I have an 01 exped. Cel is on, trouble code p401 low egr flow. I removed egr valve and started the engine, and the manifold has a lot of suction. Would this mean my ports are open and not clogged? Also tested egr with vacuum and it works fine. Should the egr open only when engine is cold? I’m beginning to think the dpfe isn’t working properly. The tubes that go from exhaust to egr and dpfe flow with exhaust gas. Also, could there be a problem with the part on the front of the engine that connects to the egr with the green vacuum line? Any help would be greatly appreciated.

  72. Dennis :

    Date: July 29, 2012 @ 3:45 am

    Hi : ). I have a 2000 Ford Excursion with the 5.4L engine, if I drive with the ac on then stop but want to restart within a 30 min time frame the suv wont start, code is P0401, Idle is perfect, no misfire, runs good, smooth, just does that when running the ac, it will turn over but wont start. I bought a DPFE but havent put it in yet, was looking for some feedback. Thanks ahead.

    ~Dennis~

  73. dennisb - Auto Tool Sales :

    Date: July 29, 2012 @ 7:33 am

    Dennis, It doesn’t make sense to me regarding the AC. Usually the AC isn’t going to be allowed on by the computer during cranking. I would check the fuel pressure when the problem after the vehicle has been off awhile. The fuel pressure should not go all the way to zero. Sounds to me like the pressure may be bleeding down. Usually it’s the fuel pump when this problem occurs. Good Luck.

  74. matt :

    Date: August 16, 2012 @ 8:28 pm

    I have a 2003 Expedition 4.6 these are the codes I am getting P0125, P0401, P0303 & P0316…changed #3 & #4 ecm, egr…what else could it be I am thinking of changing DPFE but not sure if I should spend the money & also have heard do not buy the aftermarket one…can I please get some help this truck is costing me!

  75. dennisb - Auto Tool Sales :

    Date: August 17, 2012 @ 7:18 am

    Matt, The ECM (Electronic Control Unit) also known as the computer, hardly ever fails and there’s not one per cylinder. I’m thinking you meant to say #3 & #4 coils. As far as the EGR – like this article points out, EGR low flow is usually because of intake ports clogged NOT a faulty EGR. Along with restricted EGR ports in the intake, the DPFE is also a very common cause of the P0401 code.

    The P0125 has to do with the engine not reaching operating temperature quick enough to meet the computer’s predetermined “parameter” or specifications. I would check the coolant level and the thermostat operation. If the coolant is low find out where it’s going… leaking? burning is a cylinder? Is the thermostat allowing the engine to heat up quickly before opening and allowing coolant flow?

    The P0401 is covered in the repair article above in more detail.

    The P303 is a misfire code for the #3 cylinder. Misfires for particular cylinders are usually caused by a bad coil or spark plug. A mechanical issue like low compression (from worn rings or valves) could also cause a misfire code for one cylinder. If in doubt I would do a compression test and maybe a leak down test. The P0316 means that the computer is seeing a lot of misfires when the engine is first started up. Excessive misfires within the first 1,000 revolutions will trigger the P0316 fault code. I would concentrate on the P0125 and the P303 first. After fixing the problems causing those codes I would recheck. At least the P0316 should be taken care of when the number three misfire code is taken care of.

    Aftermarket DPFE – In the past I’ve seen Ford OEM (Original Equipment Manufacturer) parts re-boxed and sold as aftermarket from a parts store. I’m not sure if anyone still does that. In all likelihood today, the parts are probably going to come from China. The fact is that China is very good at taking our products and “backwards engineering” them. They produce very good quality in many cases and can sell at very low prices. If I were purchasing a DPFE today, I would check to see what the price difference is between the dealer and several parts stores. Keep in mind that the parts stores may offer a better/longer warranty than the dealer. Also the labor involved to change a DPFE is minimal, so if it had to be changed out again, there’s no great loss of time. Good Luck.

  76. Timothy T :

    Date: August 23, 2012 @ 7:46 pm

    hi i have a 97 expedition 5.4 it keeps giving me a code for cylinder 2 missfire i changed the coil and spark plug on this cylinder 3 time i also checked my injecters which are good. do you have any idea what might cause this problem. i also have an egr flow insufficent which i will check my dpfe tomorrow

  77. Timothy T :

    Date: August 23, 2012 @ 7:52 pm

    dennisb i also had my father in law check the compression on all my cylinders he said they were good. it also gives u code p1000

  78. dennisb - Auto Tool Sales :

    Date: August 23, 2012 @ 7:59 pm

    Timothy, I would swap two of the injectors and see if the code changes cylinders. It’s also possible that oil could be fouling the plug. The P1000 is for misfires on first start up. For the low flow I would check the passages and DPFE. Good Luck.

  79. Andre delmast :

    Date: September 2, 2012 @ 7:13 pm

    Thank you. With a bad economy it really helps when people give good free do it Yourself advice.

  80. jason z :

    Date: November 26, 2012 @ 11:44 pm

    Hi Dennis, I have two problems my 00 expedition with the same code P0401 like mostly everyone here and like you suggested I cleaned the two ports which were clogged. The code still comes back don’t know if I should change the egr valve and dpfe? My second problem is all the lights inside and headlights dim on and off at idle or driving and also the battery light keeps blinking on and off. I changed the alternator and no luck still has the same problem. Can’t find to fix the two problems, I took it to the ford dealership and they couldn’t find any electrical problems and they said the alternator is producing to much amps and should be changed. Any help will be appreciated.

  81. dennisb - Auto Tool Sales :

    Date: November 27, 2012 @ 7:04 am

    Jason, the ports may still be partially clogged. I’ve seen well experienced technicians clean those ports inadequately. I would recheck them unless I was 100% sure they are clear. It’s possible the battery light may come on if the idle goes down too low. I would pay attention to when the light comes on. Also it’s possible that the alternator is charging but has a bad diode. If the problem does not seem to be low idle related, I would take to a shop that uses a tester that can examine the diode pattern. Good Luck.

  82. jason z :

    Date: November 27, 2012 @ 8:44 pm

    Thank you for knowledge and it was the ports plugged a little bit and fixed the p0401 code. Ok so I got back my 00 expedition today took it to ford dealership about the dimming lights going high and low and the only thing they could come up with is the alternator is putting out to much voltage and COULD BE BAD? This sounds fishy to me if the there was too much voltage wouldn’t the lights be brighter not like it feels like its going to die when driving? So I bought a new battery and alternator put them in and still having the same issue. Not sure what else to look for or change out to fix this problem?

  83. dennisb - Auto Tool Sales :

    Date: November 28, 2012 @ 6:27 am

    Jason, it is normal for the lights to dim some at idle and get brighter when the RPM’s are higher. Perhaps, if the battery and charger are not causing a problem like no crank or needing to be jumped off I would look for other causes of the low idle. On Fords, low idle is most often caused by the dirty throttle plates and/or a carboned up IAC (Idle Air Control) motor. Good Luck.

  84. Jason :

    Date: December 9, 2012 @ 10:42 pm

    Thank you for the advice my 2000 expedition is now check engine light free. My egr ports were plugged and needed a new thermastat. But still have one issue about the dimming lights when running. I changed out the alternator twice along with the battery. The lights are fine if you disconnect the negative battery cable but once you connect it again the dimming lights start and the battery light blinks. Not sure what can be the problem if anyone can please help?

  85. nicole :

    Date: April 23, 2013 @ 10:19 am

    Hi Dennis important having troubles with my 01 expedition. when im driving it it seems like im not gettin enough gas. my cel is not coming on. i took it to auto zone an it through a code And we fixed that with a new fuel pump and fuel filter. It still runs like bad. i took it to a shop and thy did a diagnostic on it. it showing a misfire but didn’t say where. When it tested the egr the truck shut off and failed it. We have checked the egr with a vacuum line an it shut the truck off. What should i do. i took it back to auto zone and it is no longer shows any codes but still isn’t running rimy sister in law has a 97 expedition and other was doing the same thing. hers ended up being an 02 sensor.. any thoughts?? thanks

  86. dennisb - Auto Tool Sales :

    Date: April 23, 2013 @ 3:16 pm

    Nicole, sometimes a misfire is felt with Ford’s before the misfire code is triggered. See our article on Mode 6, which may help your technician find the problem cylinder without waiting for a hard code to be set. Click the following – Mode 6 Ford

  87. Scott :

    Date: April 24, 2013 @ 11:54 pm

    Dennis, Having P0401 and P1151 with my 2000 F150 with 5.4 . Replaced DPFE and still get codes.When I apply vacuum to EGR valve at an idle motor begins to stall (so I’m assuming passages ar clear). If I try to hold 1800 rpms while parked, motor stumbles down like EGR valve is opening up. My question is do you think I’m dealing with a vacuum leak or is the P1151 (o2 sensor)messing with the EGR valve? Or?

    Thanks for you help!

  88. dennisb - Auto Tool Sales :

    Date: April 25, 2013 @ 7:33 am

    Scott, there may be several issues. I’ve done the exact same test before and still ended up finding clogged EGR passages. I would bet, that the EGR passages are surely, at least partially clogged. Only partially clogged EGR passages WILL set the P0401 code. I’ve cleaned these passages before and missed some build up and the code returned. That’s why spraying FI (Fuel Injection) cleaner down the throttle body does absolutely no good to clean these passages. The P1151 is a separate issue, most likely the O2 itself. We have an article on that code as well. Once these codes are resolved, it’s likely that the running issue with the stumbling will be also. I would recheck at that time. If the stumbling continues there could be a misfire that has not set a code yet. That’s what Mode 6 is good for on the Ford’s in particular. We have an article on Mode 6 and finding a misfiring cylinder before it sets a code. You may not have to go there if fixing the problems causing the present codes takes care of the stumbling. Good Luck.

    P1151 Oxygen Sensor Code

    Mode 6 Find Misfires before code has set.

  89. MDeppe :

    Date: June 18, 2013 @ 7:29 pm

    Hi Dennis,
    I have a 2001 Ford Expedition 5.4. I just had to replace the muffler because it wouldn’t pass inspection. About 4 days later my CES light came on. Had autozone check it for me and got EGR code P0401. Could the new muffler have anything to do with this ?

  90. dennisb - Auto Tool Sales :

    Date: June 19, 2013 @ 6:38 am

    The main cause of the P0401 in this model is covered in the article. Replacing a muffler may change the back pressure a little by restoring it to where it should have been all along. But I can’t see this having anything to do with triggering the code.

  91. Thirdgear :

    Date: June 27, 2013 @ 9:55 pm

    2000 expedition.
    Hello, I’m new here.. My expedition keeps throwing a p0452 code. And common issues that u know about with these codes and vehicles? Thank you.

  92. dennisb - Auto Tool Sales :

    Date: June 28, 2013 @ 8:37 am

    The P0452 is a Fuel Tank Pressure Sensor fault code signaled by the vehicle’s computer when it performed a self test and the readings were not within specific parameters. This could have been because of no signal at all due to an open circuit in the fuel pressure sensor or somewhere in the wiring. Or the readings were not within certain limits. If the tank was recently removed to replace a fuel pump or fuel sending unit for example, the fuel pressure sensor could have been accidentally broken during R & R (Removal and Replacing) of the tank. Also the wiring can be chaffed if not routed properly. The bad news is that the sensor is on top of the fuel tank which requires removal of the tank to gain access. If the wiring especially near the sensor looks good the most likely cause of the code would be a failed sensor. Good Luck.

    Ford Fuel Tank Pressure Sensor

  93. Thirdgear :

    Date: June 28, 2013 @ 10:11 am

    Eww, that’s gonna suck, but thanks a million.
    Hey, 1 more question. There is also a lingering 401 code. (That’s how I found this blog). I know you’ve already hit in this code a hundred times, but here’s my issue.
    Replaced egr, DPFE, egr solenoid, cleaned out ports thoroughly, removed and inspected DPFE tubes. CEL still comes back on. Any further suggestions?
    Thanks again man!

  94. Thirdgear :

    Date: June 28, 2013 @ 10:22 am

    Oh yeah, and it stumbles with vacuum applied at egr. Tested vacuum from feeder hose and its about 13 hg at 2000rpm.

  95. dennisb - Auto Tool Sales :

    Date: June 28, 2013 @ 10:30 am

    All I say is that if the ports are clogged even slightly the code will set. Good Luck.

  96. Thirdgear :

    Date: June 28, 2013 @ 10:42 am

    Ok thanks. I’ll double check em.

  97. Percy's Mom :

    Date: August 18, 2013 @ 9:21 pm

    Just wanted to thank you for your site and all the great tips! My husband and I have NEVER been successful at fixing anything that is powered by gasoline (ie: 38 years of marriage-38 lawn mowers!!) After trying EVERYTHING to fix our PO401 code on his 1997 Ford Ranger (with 347,432 miles on it)your tips on cleaning out the ports worked and the light, after 1yr being on, is now off. Thank you, Thank You

  98. dennisb - Auto Tool Sales :

    Date: August 19, 2013 @ 7:33 am

    Hey, thanks for taking time to come back and let us know how your repair turned out. That’s funny about the lawn mowers! Glad the tips were useful. It’s good to know that our articles help. And wow over 300,000 miles on a Ranger… that might be some sort of record :)

    Sometimes it’s a challenge to respond to comments while we are so busy. We’ve been doing more videos on our DenLors YouTube channel and have been being more active on our https://www.facebook.com/DenLorsTools (Like us there to keep up with discount info). In addition we’ve started a new Auto Tool Website called WiseAutoTools.com. Our new website has a great design and has many more functions that allows us to offer wholesale pricing for businesses that do repeat business with us on certain items like Jeep door handles, thread repair kits, mechanic’s disposable gloves etc.

  99. Mark :

    Date: September 4, 2013 @ 6:55 pm

    I have a 99 ford expedition that runs fine and then dies like its running out of gas. Replaced the fuel filter but still happens after sitting for a while starts back up runs fine until problem repeats.

  100. dennisb - Auto Tool Sales :

    Date: September 5, 2013 @ 11:00 am

    Not related to the P0401. I would check the fuel pressure when it acts up.

  101. Todd :

    Date: September 6, 2013 @ 10:07 pm

    I have a 2000 expedition 4.6 losing water. Does not leak, no puddles. Oil on dipstick is good, no bubbles, or over-flowing of coolant from reservoir. Have not done compression check yet. Does have very noticeable exhaust leak up front, and related or not…have not had heat since I’ve owned vehicle. Thank you for any suggestions.

  102. dennisb - Auto Tool Sales :

    Date: September 7, 2013 @ 9:13 am

    Not related to the P0401 issue. For other’s reading this, I want to answer your questions but would appreciate it if there’s a more closely related article for the question, I would prefer it be asked there on that article. That way we can stay on topic better. Just use the Google search or look through the categories. Thanks.

    I would pressure test the cooling system using a coolant pressure tester (Use our site search box – COOLANT PRESSURE TESTER). A small leak may not form a puddle. Also if there’s no leak when pressure testing, I would do a carbon test to see if there’s any exhaust in the cooling system (Use our site search CARBON LEAK TESTER). A blown head gasket does not have to mean there’s water in the oil. If there’s a small internal coolant leak into the exhaust, the exhaust may vaporize it and there may not be a noticeable cloud out the tailpipe. Let’s hope that it’s just a minor leak though that can be located with the pressure testing. The heater problem is probably because the cooling system is low on coolant or there’s an air lock. Our most popular car repair blog article in the cooler months of the year, goes into more detail and has saved our reader’s a lot of money. See our Heater Blows Cold Air car repair article (there’s 2 pages so be sure to read both of them). Good Luck.

  103. leo :

    Date: September 17, 2013 @ 11:27 am

    Hi I hope you can help me my 1999 f150 4.6 every time that I start no matter how many times it accelerates to 2000 rpm this is normal, there is something wrong change the idle air control and still the same.
    the truck run perfect but I am concerned.

  104. dennisb - Auto Tool Sales :

    Date: September 17, 2013 @ 11:56 am

    Leo the computer will command higher RPM’s upon cold start up. This is similar to how chokes worked on carburetors. After the vehicle warms up the idle will come down on fuel injected vehicles, unlike on carburetor vehicles where you had to release the choke by giving a quick stomp on the accelerator pedal.

    I would say 1500 to 2000 would be around normal. However, 2000 RPM’s when it’s not cold outside seems a little on the high end. I would check for any codes, vacuum leaks and clean the throttle plates. If you are still concerned, you may want to take it to the Ford dealer to see if there are any software updates that may bring the RPM’s down slightly on first start up. Good Luck.

  105. leo :

    Date: September 17, 2013 @ 3:14 pm

    thanks for responding so quickly tomorrow go to the dealer gracias amigo…

  106. Blake :

    Date: November 21, 2013 @ 10:43 pm

    Hey I am having a problem where my 2000 ford expedition cranks but doesn’t start. Someone told me about the possibility of the ports being clogged and I went in and cleaned them as you described and they were very dirty. It’s been a week now and it just started to get cold and my son and I were leaving a scouting event and the truck would crank but not start. Finally after about 5 minutes the truck roared to life. I replaced the EGR valve while I had the whole thing apart but didn’t touch the DPFE.. Is this hesitation to start related to anything you are talking about here?

  107. dennisb - Auto Tool Sales :

    Date: November 22, 2013 @ 6:43 am

    No. Usually the DPFE or low EGR flow does not cause much of a drivability issue. Here’s a quote from the article above.

    ” Most of the time performance issues aren’t noticeable. Sometimes pinging upon acceleration can be detected if the DPFE is not working properly.”

    I would suspect a faulty fuel pump with a slow to start vehicle. Of course I would scan for codes and check fuel pressure and go from there. Also cleaning the throttle plates may help with a slow start. Here’s a link to an auto repair article with more information on the Cranks but doesn’t start condition.

  108. nathan :

    Date: December 2, 2013 @ 12:25 pm

    i got the same problem on my 97 expedtion 4×4 4.6 it tells me a restricted egr valve should i take these same steps to fix my problem

  109. dennisb - Auto Tool Sales :

    Date: December 2, 2013 @ 12:55 pm

    Nathan, if you have the same code for restricted or low EGR flow, then yes I would. Good Luck.

  110. NICK :

    Date: December 23, 2013 @ 3:14 pm

    I have a 2005 ford expedition and my check engine light came on,so I hooked it to a computer and it showed I have a misfire on spark plug number 4.took it to the shop and nothing is wrong wth the plug or coil.would a vacuum leak on the brake booster cause that plug to misfire and would it cause the truck to run a little skippy and have trouble cranking?also I smell gas when I first crank it

  111. dennisb - Auto Tool Sales :

    Date: December 23, 2013 @ 3:40 pm

    There are many things that can cause a misfire on ONE cylinder. A vacuum leak would affect more than just one cylinder though. The problem your mechanic should be looking for is only going to affect the one cylinder. The most common causes of a misfire are usually the following with the most common to least common in order. 1. Spark plug 2. Coil or spark plug wire 3. Fuel injector. 4. Mechanical issue causing like low compression. 5. Computer or wiring issue.

    Smelling gas when you first start, could mean a leaky fuel injector. Good Luck.

  112. rob :

    Date: December 30, 2013 @ 3:29 am

    After watching video I got brave and removed throttle body and cleaned as you instructed. Now I have what feels like a misfire rough idle. Drives fine at all speeds till coming to stop. Feels like it wants to stall. I had p0401 and p1131 and have changed b1s1 oxygen sensor and dpfe and egr valve and IAC. It was only after cleaning throttle body bad idle started. Is it possible I didn’t gasket it correctly or torqued too hard and have a vacuum leak??

  113. rob :

    Date: December 30, 2013 @ 3:32 am

    BTW it was grossly clogged and got it all out…great video…I’ll check your other forums out and recommend u to my friends;)

  114. rob :

    Date: December 30, 2013 @ 3:49 am

    I apologize 99 expedition 4.6 and replaced IAC cause I broke it when took throttle body off…cel hasn’t come back on yet and idle is better but still rough.

  115. dennisb - Auto Tool Sales :

    Date: December 30, 2013 @ 7:15 am

    Not sure what video you’re referring to, but sometimes after cleaning the throttle plates it may take a little while for the computer to relearn it’s fuel strategy based on the increased amount of airflow now allowed in through the newly cleaned t-body. Of course you could retrace your steps and make sure you made no mistakes or inadvertently caused a vacuum leak.. Good Luck.

  116. rob :

    Date: December 31, 2013 @ 12:40 am

    Thx…I did create a leak..retraced steps as u said and found egr valve gasket half hanging…lol…everything good so far but have discovered at least for my vehicle that negative battery reset doesn’t work..at least not completely…advanced reset it and now cel not coming on after proper drive cycle…thx for the help and advice.

  117. dennisb - Auto Tool Sales :

    Date: December 31, 2013 @ 6:43 am

  118. Leslie :

    Date: February 22, 2014 @ 4:37 pm

    I have a 98 expedition 4.6 that for the past month or so It would start fine in the morning get to where I’m going and then go to start it again and nothing . Would happen occasionally then started doing it more and more , Code 1405 came up. Husband has not been able to figure it out . Now it won’t start at all… Lights are fine I can hear everything clicking like normal and the starter was checked and it’s fine… Help

  119. dennisb - Auto Tool Sales :

    Date: February 22, 2014 @ 5:59 pm

    The code means Differential Pressure Feedback Sensor Upstream Hose Off Or Plugged. But that will not cause a no start. If the battery tests good I would check the starter. Good Luck.

  120. fergie :

    Date: May 6, 2014 @ 1:54 pm

    I was driving it before I put a new fuel tank in my 1997 ford explorer eddie bauer edition and a new fuel pressure relieve regulator in it and now it will not start

  121. dennisb - Auto Tool Sales :

    Date: May 6, 2014 @ 2:47 pm

    Possibly a bad connection or a kinked fuel line. Time to recheck work that was performed. Good Luck

  122. Duane :

    Date: May 12, 2014 @ 9:07 am

    Thanks for the mirror picture on ports. I have been trying to clear that 401 code for months. It worked!

  123. dennisb - Auto Tool Sales :

    Date: May 12, 2014 @ 9:25 am

    Duane, glad it worked for you. Keep us in mind for your future tool needs.

  124. Doug :

    Date: May 18, 2014 @ 12:19 am

    I got a 97 F150 4.6L, that keeps on throwing PO304, & PO401 codes. I have replaced plugs, coil, wires, DPFE, EGR vac. regulator and EGR. Any ideas its driving me nuts.

  125. dennisb - Auto Tool Sales :

    Date: May 18, 2014 @ 9:10 am

    Doug, two different problems. The P0401 code is most likely plugged EGR passages. The P0304 misfire code is for the #4 cylinder. I would concentrate on that cylinder. Since you’ve already eliminated the possibility of a coil or spark plug and the fact that the vehicle is 17 years old, maybe there’s a mechanical issue. I’d check the compression. If a valve or ring is worn the compression could be low enough to cause a misfire. Good Luck.

  126. Doug :

    Date: May 20, 2014 @ 5:52 pm

    Thanks Dennis, EGR passages were plugged, did a compression ck., had no compression so I pressurized it, air came back through the intake I just had the heads done 15,000 miles ago trucks only got 180, 000 on it.

  127. dennisb - Auto Tool Sales :

    Date: May 21, 2014 @ 7:16 am

    Doug, I’m not surprised the EGR passages were plugged. Sounds like you were doing some sort of leak down test and NOT a cylinder compression test. If you truly have 0% compression (not likely) there’s a terrible mechanical failure. There would be a horrible dead miss felt.

    If the valves are open the cylinder will not hold pressure. When checking the compression test a compression test kit is used. The fitting from a hose is screwed into the spark plug hole and (with the ignition disabled) the engine is cranked over. The reading can then be seen on the gauge. You can also do further wet testing to see if a problem is with the valves or worn rings but the first readings you get doing a dry test on all cylinders will provide a good oversight of what’s going on. You don’t want to see more than 10% difference between readings from all cylinders.

  128. Doug :

    Date: May 21, 2014 @ 11:56 am

    Yes I did do a compression ck had 0 compression that’s why I did a pressure ck

  129. dennisb - Auto Tool Sales :

    Date: May 21, 2014 @ 12:40 pm

    Doug, Oh OK. Wasn’t sure if 0psi could possibly be right. And the way you described (you pressurized) led me to think that you were doing a leak down test with air compressor air instead of a compression test, spinning the engine over. You must have a horribly running engine with one cylinder completely down. I suppose it’s time to take it back to the shop that did the cylinder head to see what can be done. Good Luck.

  130. luis delbusto :

    Date: July 4, 2014 @ 12:44 pm

    I’m having the same code’s like other’s should I go ahead and replace the DPFE first and wait to see what it does after that or ahead clean out the passage way to the EGR also?

  131. dennisb - Auto Tool Sales :

    Date: July 4, 2014 @ 3:02 pm

    It’s up to you now. I’ve provided the info. Good Luck.

  132. Coop :

    Date: July 9, 2014 @ 12:37 am

    Hey Doug I have a 2008 Ford F150 4.6 L anyway it is a Autel 519 fault tool it does not give me codes I have to go to the on board monitoring system and it is telling me when I click on the EGR monitor that I have a disconnected upstream hose that’s all it says my truck has a rough idle at idle it lacks power on take off. If you take off very slow like real light pedal it’s ok. It did give me an oxygen sensor monitor for the B2S1 but I changed them both and now the only monitor left is the one I mentioned above there is no two hoses on the big copper pipe like the older models the DPFE looks like a tube with the two hose inlets on it on the firewall on drivers side.

  133. Coop :

    Date: July 10, 2014 @ 12:12 am

    I have a 2008 Ford f150 4.6L V8 and I am getting a monitor on my E.G.R saying the upstream hose is disconnected my truck does not have these hoses or a DPFE sensor and if it does where are these things I have looked all over the motor and they are not there can you help me out with this I guess it’s something new they started doing in 2008 on the new style body?

  134. dennisb - Auto Tool Sales :

    Date: July 10, 2014 @ 7:55 am

    Coop, this article is for the older Fords. Your 2008 Ford F150 is completely different. Your DPFE is built into the EGR. Your Autel may not be current for the model you’re working on also. We sell OBD II scan tools that may be more helpful compared to what you are using.

    2008 4.6 Ford EGR with DPFE built-in.

  135. Coop :

    Date: July 10, 2014 @ 3:15 pm

    Ok thanks man is there any way of testing the EGR to tell if the DPFE is bad or is the the EGR that would be bad something sounds like it’s clogged up I cleaned the TBI there is a tube inside of it that goes to the EGR. I put a coat hanger in about half way it came out dirty would this be my problem maybe?

  136. dennisb - Auto Tool Sales :

    Date: July 10, 2014 @ 3:21 pm

    I don’t think that this design has that issue like the older models. I’d just replace the EGR/DPFE assembly because that’s the only way you can purchase it. You could clean the passage while the EGR is off, but again, I don’t think this design is likely to get restricted. Good Luck.

  137. Wise Auto Tool Blog » Ford Trouble Codes P0125, P0401, P303 and P0316 :

    Date: July 12, 2014 @ 11:21 am

    […] That would have made more sense. As far as the EGR – like my original article points out (about Ford EGR Low Flow) EGR low flow is usually because of intake ports clogged NOT a faulty EGR. Along with restricted […]

  138. Ed with 2001 E150 :

    Date: July 12, 2014 @ 11:31 pm

    I have a 2001 Ford E150 with 4.2 liter engine with P0401 code. EGR vacuum regulator looks ok. Tubes look ok. EGR valve looks ok. Passages look great. I’m just sure I have proper EGR flow. I have replaced the DPFE sensor twice with BWD part # EGR631.

    I teed in a vacuum gauge right next to the EGR valve so I can watch the vacuum signal go from 0 to 7″ HG as I drive.

    There is a three wire harness for the DPFE. 1st wire is always 5 volts. 2nd is always ground. I thought the 3rd should fluctuate from .5 volts to 5 volts depending on the exhaust gas flow. This would tell the computer that the flow is adequate. BUT, as I drive, this voltage stays about .5 volts.

    The EGR valve bolts right to the intake. I’ve run a big 5/8″ bottle brush through the connection point.
    Question about the two tubes that go to the DPFE sensor: Is there an orifice in either tube? I’ve flushed water through each small tube and through the large ends.

    Do I need to buy another DPFE? Maybe from the Ford dealer?

    Can I test the DPFE somehow.

    What can I try next to clear this code?

    Thanks for all you’re doing.

  139. dennisb - Auto Tool Sales :

    Date: July 13, 2014 @ 9:38 am

    Ed, the hoses should be replaced with DPFE hoses (not any other type) if they show signs of breaking down There are no orifices in the hoses, only inside the DPFE. The OBD II systems test themselves very well. The P0401 means there is insufficient EGR flow. The Ford differential pressure feedback electronic (DPFE) system keeps a check on the exhaust backpressure and the DPFE typically sends a 3-5V signal to the PCM. (If the signal is less than 3 volts would indicate a vacuum in the exhaust system. Not common. 5.0 volts is the high reading on the scale. High readings at idle indicate an exhaust restriction, low readings an exhaust leak. The most common cause is from ports clogged. The port you’ve cleaned is NOT the one that typically gets clogged. I’d remove the throttle body and clean the ports that lead to the EGR passage. It’s not likely that you have a defective DPFE since you had this code before you replaced it. And you still have it now. The code is simply being triggered because of a clogged passage and the computer seeing readings that are outside the expected parameters. If you decide to pull the T-Body, I’d appreciate an email with the pictures of the clogged passages once you remove the throttle body. Let me know if you have taken some digital pics and I’ll send you my email address. Thanks and good luck.

  140. Ed with 2001 E150 :

    Date: July 16, 2014 @ 1:37 pm

    The two rubber or maybe silicone hoses are intact.

    This van has the EGR located well below the throttle body, not on the throttle body. I removed the throttle body and don’t see anything obvious.
    A friend started the van and ran it while I held my thumb over the EGR port. I used a vacuum pump to open the EGR valve and the EGR sucks like crazy. Again, I think I have proper EGR function, but maybe something wrong in the DPFE system to let the computer know that there is flow.

    Is there any way to bench test the DPFE switch? I tested resistance between the three electrodes. I expected to see a fluctuation in the ohms as I blew or sucked on the two tubes, but nothing. Thanks again. I was surprised how quickly you responded last time.

  141. dennisb - Auto Tool Sales :

    Date: July 16, 2014 @ 1:59 pm

    I don’t know of a way to bench test a DPFE. I never had the need to test one like you want. If you are sure that the small EGR passage is completely clear that goes from throttle body to the EGR (both should be off at the same time when checking and cleaning) I have no other suggestions. Sorry I was unable to help. Good Luck.

  142. Ed with 2001 E150 :

    Date: July 20, 2014 @ 9:55 am

    I found a way to test the DPFE:

    Forget about testing resistance as I did on the previous post. With the wire harness plugged in, connect a voltmeter between battery ground and the signal wire (I shoved a sewing needle through the wire). Disconnect the two tubes from the DPFE. Connect maybe a 2 foot hose on the smaller tube of the DPFE. Turn on the ignition key (my engine doesn’t need to be running). Apply suction to the hose and watch the voltage change from about .5 volts to 5 volts.

  143. Ed with 2001 E150 :

    Date: July 20, 2014 @ 10:03 am

    In an earlier post, I asked if there is an orifice in either of the two tubes that go to the DPFE. Now, I think there might be an orifice in the larger EGR pipe located between the two tubes. I want to cut a tube apart just to look!

  144. Ed with 2001 E150 :

    Date: July 20, 2014 @ 10:21 am

    Ok, I haven’t fixed my problem yet, but I am really getting educated. I understand that the EGR on my 4.2 engine lets exhaust gas straight into the intake manifold without first going through the throttle body. From the cavity of the intake manifold, the gas is directed into 6 individual EGR orifices that are pressed into each primary port of the lower intake manifold. These orifices might be 1/4 inch diameter and it is said that they plug up from whatever gets sucked through the PCV valve. I’m wondering of 3 or 4 of my orifices might be plugged.

    Here in Colorado, it looks like a good day to roll up my sleaves and disassemble my intake manifold. I’ll keep you advised.

  145. dennisb - Auto Tool Sales :

    Date: July 21, 2014 @ 7:23 am

    Ed, thanks for the updates. Curious to know if the passages are causing the issue like I originally suspected (and still suspect). Good Luck.

  146. Denlors Auto Blog » Blog Archive Common Ford Problems and Specialty Tools | Denlors Auto Blog :

    Date: July 26, 2014 @ 4:50 pm

    […] other common problems with Fords are EGR low flow codes, which can mean EGR passages are clogged up and in many other cases it could just mean that the […]

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