Hey all,
I have a 97 F-150 4x4 with the 4.6. I have been fighting a P401 code for awhile now. I just replaced the EGR valve, and cleared the code. The code came back on, so I checked the voltage of the DPFE, and its at 4.9 volts (Chilton says between 4-6 is good)
The only other things I can think of would be I mixed up the rubber lines that run from the DPFE to the EGR tube, or I have a vacuum leak.
Any other ideas?

Thanks a lot!

 

Sure , The 401 code is either one of two things .

1. The most likely cause is your DPFE giving the PCM a bogus reading when called upon to report. When they get old the sensor itself sticks within the housing - Volts don't matter when the sensor sticks.

2. Your throttle body elbow ports to the EGR could be getting clogged up. The 4six is known for this problem . So pull the throttle body and elbow and clean the ports with some good automotive pipe cleaners. If that doesn't cure the code from re-occurring , then replace the DPFE.

You have to get the updated DPFE from a dealership - third party venders DO NOT carry the updated one.

Heres the clean your TB link -

http://www.fordf150.net/howto/throttlebodyclean.php

 

you replaced TOOOOOO much. P0401 is 9/9.1 times a bad DPFE sensor... to do a quick check to find this out...


1. take off the old DPFE

2. using the palm of your hand tap the DPFE with the inlet holes toward your palm

3. Water? Yup, bad DPFE.

Another way to do it is to pull the data on the DPFE sensor... if it's anything but ~.9 volts with engine off, it's 9/9.1 times a bad DPFE.

Oh and jbrew's right, the volts don't matter... chilton is telling you to check that the volts going to the DPFE is between 4 and 6... and typically 5V. The output is the reading you need to get.

 

Thank you guys for helping me out! I really appreciate it, and believe I saw some watery gunk in the DPFE ports, so I will go replace this. How much can I expect Ford to charge me? It was about $85 with my military discount at NAPA, but I returned it after I did the voltage test.

Thanks once again!

 

Parts
. OEM Part
. Price
Pressure Feedback Exhaust Sensor
.
. Pressure Feedback Sensor
. F77Z9J460AB
. $112.47
Notes
Labor
. Skill
Level
. Mfg.
Warr.
. Std.
Pressure Feedback Exhaust Sensor
.
. Replace
. B
. 0.1
. 0.3
Notes
.
. Does Not Include: EEC Quick Test Or Pin Point Test Diagnosis Time.

You might get one cheaper , but I doubt it...

 

Do you have the aluminum one? You can crack her open and fixer. My stocker has about 238,000 miles on it

 

I am one of the unfortunate with the ****ty black plastic one.

 

eh, the plastic one isn't bad... it makes a nice RO holder when the wind gets a bit much in the shop...

 

That sucks !! You can't swap them either according to Scorpio -

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

 

 

JBREW, How do you repair that Alum. DPFE?

 

I just popped the rivet heads with a 3/16 drill bit. There aluminum, I had them all popped in about 15 seconds. Then it splits right apart. Don't drill all the way threw or you'll damage the gasket.

Clean it up inside and put it back together - make sure that yellow piece of plastic inside is glued to the sensor itself before reassembly. Use screws to put it back together and finally apply some "sensor safe" RTV to the outside seam - it cant leak.

 

Thanks! What did you use to clean it? Solvent,contact cleaner,etc?

 

I took my DPFE apart today(Alum.) and cleaned it. It was quite a mess inside. Moisture, some type of corrosion, and carbon. Got it cleaned up back together. Seems to be working OK. No CEL.

 

Glad you gotter fixed , but you won't really know until you complete 3 drive cycles without a light if you rebooted.. Try to report back to this thread if you have problems with it so others know.

Thanx