A little help needed on P0401 code!

[sweigl]

I pulled a P0401 code on the 2002 explorer and saw online where most people say it is the DPFE sensor even though the code indicates EGR valve. I replaced the sensor (not the tubes) and cleared the code. Still getting the same code. Do I need to replace the ERG valve now? Is this a job for a newbie?
Thanks

 

[Ted22]

There is a port on the throttle body that gets clogged... Clean that first before you throw parts at it. So basically the exhaust recircs through the system first in the morning... The differential pressure flow exhaust (DPFE ???? Not positive). Tells if its working correctly. More than likely the passages have gotten clogged... The DPFE is a sealed electronic part, and doesn't fail frequently... IMHO. In anycase a 1/2 can of carb cleaner is cheaper!

 

[Ted22]

P.S.

I've never had to do on my explorer, only 77k... Did have to do on my f250, after I got a DPFE, egr, etc

 

[esclamada]

The EGR pressure sensor fails most of the time with p0401 code on explorers. The EGR valve seldom fails because it's mechanical and just needs to be cleaned. It can be done as DIY cleaning, use a new gasket when putting it back. If codes comes back after cleaning the EGR valve (and new sensor), the EGR tube might have leaks.


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[mrfixit1]

check to see that the egr valve is working it pretty common that the dpfe goes bad but you ruled that out .you did not say what motor you have? to see if egr works follow green hose from egr valve to egr solenoid and see if at the solenoid you will see a green hose and a red hose pull these off solenoid the red hose should have vacuum with engine running if it does jump these hoses across it should make engine run rough or stall if this works than your egr system is working .hope this helps I have seen broken soleniod hoses also.

 

[sweigl]

I have a v6 4.0 (?) liter. What does the EGR valve look like?

 

[mrfixit1]

woh! I think you gotta take it to someone. Sorry if I gave you too much Information.

 

[Ted22]

if your not familiar with the egr, invest in a factory service manual... the real one, will be $200-250 on ebay, but worth it!

 

[DAT05EXPLODER]

at very least, use the search function and read as many threads as you can until you feel familiar with the part. I am pretty mechanical, but run into things i normally have never dealt with and learn so much from reading forums and people who have experienced the same problem. many of those threads will have some pictures and give you a good visualization of the problem at hand.

 

[sweigl]

Although not really mechanically inclined, I don't mind "trying" it myself if I can understand the process of what to do. If you think it's a job suitable for a person of that nature, I appreciate any info you've got. I just don't want to be "tearing" the engine apart and hope I can put it all back together propertly.

 

[BigRondo]

if your not familiar with the egr, invest in a factory service manual... the real one, will be $200-250 on ebay, but worth it!

I scored my Factory Service Manuals on eBay for $40. Gotta shop around and not grab the first set you see:

 

[DAT05EXPLODER]

the egr valve isnt that big of a job IMO. should be located on the throttle body, im more familiar with the 4.6 but the 4.0 cant be too much different.

 

[BigRondo]

I will send info on changing the EGR valve tomorrow.

Gotta get some sleep right now.

EDIT: Check you PM, I just sent it. Good night. :

 

[mrfixit1]

I never said that the EGR valve is bad the things I told you were how to check out your problem Please follow my instructions and you should find the problem I am a Ford Senior Master Tech and work for Ford for 30+ years.

 

[2009KVFD976]

Ive already replaced EGR valve, DPFE sensor, intake gaskets, cleaned the EGR tube and ports and checked all vac lines to/from EGR/EVR with a persistent P0401. Also did a voltage check on DPFE and EVR which passed. anything else i need to look into? I took out my upstream O2 sensor from the driver side and the tip is very white, what is goin on there? Too lean/rich or just time to replace them? I do have an actron CP9580 and not sure where short and long term fuel trims are supposed to b at.

 

[2009KVFD976]

Ive already replaced EGR valve, DPFE sensor, intake gaskets, cleaned the EGR tube and ports and checked all vac lines to/from EGR/EVR with a persistent P0401. Also did a voltage check on DPFE and EVR which passed. anything else i need to look into? I took out my upstream O2 sensor from the driver side and the tip is very white, what is goin on there? Too lean/rich or just time to replace them? I do have an actron CP9580 and not sure where short and long term fuel trims are supposed to b at.

 

[mrfixit1]

the egr valve is new now it should be working it pretty common that the dpfe goes bad but you ruled that out .you did say its a 4.0 engine to see if egr works follow green hose from egr valve to egr solenoid and see if at the solenoid you will see a green hose and a red hose pull these off solenoid the red hose should have vacuum with engine running if it does jump these hoses across it should make engine run rough or stall if this works than your egr system is working .hope this helps I have seen broken soleniod hoses also. The code p0401 means no egr flow if you can read the the voltages on pid dpfeegr on your scanner it should be 1.00 volts plus or minus .09 then with the red and green hoses jumped and car running check readings again it should go up to any where between 1.09 to any were near 4.0 but it should run bad at idle the voltage will go higher as engine rpm is increased.I hope you are learning something here i am trying to put it as clear as possible for you.it is very important that this runs bad with these two hoses together if not results will be bad if it don't run bad then get a vacuum source from a pump directly to egr to see if it opens and idles rough.

 

[accountanne]

I would like to ask if you could please send me a copy of the pages in your maneuls on replacing the EGR valve etc- I am have the same problem but I have just bought parts and have not attempted repair yet. I would really appreciate it. Thank you.

 

[mrfixit1]

Wish I could

This information is in my head I don't have shop manuals on hand they are online and in the public library sometimes good luck.

 

[mall]

I never said that the EGR valve is bad the things I told you were how to check out your problem Please follow my instructions and you should find the problem I am a Ford Senior Master Tech and work for Ford for 30+ years.

That explains why you are so quick to tell someone to take their vehicle to a Ford Senior Master Technician to get it fixed.