I searched and got nothing. My Mom's Mountaineer with a 5.0 V8 keeps giving us the P0404. Code is linked to egr stuff. Valve and DPFE sensor have been replaced in the past, but it still comes on. Any ideas? The moron at Autozone told her she needed a new EGR valve....they know nothing. The truck runs pretty good, mileage is a little low though.

 

It's prolly the same fix that a 401 code usually is - Replace the DPFE sensor.




She gotta a bad one. Ford updated the DPFE recently and you could only get the updated ones from the dealership ..

 

P0404? What?

 

Hrmm Ill give it a shot.

Quintin, she has the print-out in her purse, Ill have to give you the details later.

Thanks fellas

 

the throttle body is most likely the problem. it is easy to take off and cleen it. the shop should charge bout $80. but it only take about 30 min. to do. i did on a 97 4.6 and 02 5.4 in a f150s and they both took about same time to do, very easy to take apart and put back together.

 

I took some time to search for more exact info on the 404 code and find it hard to get anything more than what the code charts say.
I think from what I did find that it may refer to a fault with the EVR device or operation.
Look at jbrew's drawing and look for the EVR. It is a device that the PCM electrically operates by pulsing signal, to gate vacuum to the EGR and controlling it's operation.
I have searched for more specific application to a 5.0 Mount. truck but no better luck so far.
Good luck with it.

 

Fords engines have a common problem with the DPFE's, Turned out on my Gpa's 98 F150, after i cleaned the throttle body, Replaced EGR valve, that it was a DPFE. Im thinking that with his 2001 Lincoln Towncar that it is the DPFE on it, it is giving a P0401 at times and the next ride P0402 both Excessive flow and insufficent flow, I tested the EGR valve by applying vaccum while running, and the engine stalls out, Any ideas, Do you guys think it is a DPFE, Btw im new to the forums, sorry for the long post, I guess i am off to a good start, I am 16 and working on cars and trucks...

 

Hello, look at jbrew's drawing, and study it.
What you need is the explanation of how the system works, how the diagnostics work, then you should see most all the reasons there can be faults.
If your going to work on modern cars and trucks, you need to begin at about this point for self education. After awhile you will see how much eaiser it is to solve faults.
I would suggest you go the the Motorcraft website and down load the OBDII manuel for the year you are working on. Waring it is about 100 pages +/-.
Once you have it, the info only changes from year to year a bit until 04 when the new CAN system came into use.
It contains a lot of 'how it works' information as well as references the codes to the faults.
See my reply to your kind of fault, in another thread about 401/402 codes.
Good luck. .

 

Try this --------

= http://www.fordscorpio.co.uk/egrmonitor.htm

 

Wow guys, I thought this thread was dead. Thanks for all the advice. Im going to get a new DPFE from the dealer tomorrow morning, Ill let you know how it turns out.