code egr valve insuficient flow problem
New User
Joined: Dec 2005
Posts: 11
Likes: 0
It's a Differential Pressure Feedback sensor used to measure flow through the EGR tube. Here is a link that explains it pretty well.
http://www.obdiicsu.com/Studies/1999...ies/study.html
On my truck it is just upstream of the EGR valve.
http://www.obdiicsu.com/Studies/1999...ies/study.html
On my truck it is just upstream of the EGR valve.
Junior User
Joined: Nov 2005
Posts: 53
Likes: 0
From: Florida
Thank you for the site reference. I cleaned my dads 1996 4.2L yesterday. the egr was attached to the intake so I removed it, cleaned all ports. While i was taking the tube off the egr i noticed the nut was not even tight. Reinstalled everything and the truck runs fine. Smooth idle better throttle response. He did call me back last night to say that the check engine light came back on. So we will have to investigate this.
Senior User
Joined: Apr 2004
Posts: 336
Likes: 0
OK, I had code P1406 and the guys at Autozone told me it was the EGR valve so I replaced it, cleared the code and the "Service Engine Soon" light came back on. A different code reader said it was the DPFE senser but I have no idea what the thing looks like or where it is to know where to start. Does anyone have a clue other than directing me to some prehistoric schematic that makes no reference to what the thing looks like? I'm not too engine savy to any help would be great.
FTE Legend
Joined: Aug 2004
Posts: 37,887
Likes: 20
From: North Central Rural Sask.
On my truck with the 4.6 litre in it, the dpfe sensor is the sensor right beside the throttle body, it is pretty easy to see. You could always check out the part at a parts store then go search for it on your truck too!
Senior User
Joined: Apr 2004
Posts: 336
Likes: 0
I found the DPFE sensor and it was melted on one side, right above the hose inlet. There is nothing that is anywhere close to this piece of plastic to cause it to melt. The only thing that it could have melted it is the exhaust gas itself...but why? Isn't that what this part is supposed to measure...exhaust gas? I got code P1406 after I had a new muffler installed.
New User
Joined: Oct 2005
Posts: 3
Likes: 0
DPFE is the differential Pressure sensor that provides input to the PCM. The sensor is a flat silver metal or black plastic rectangular shaped device about 3 inches by 2 inches with one 3 wire connector and two vacuum lines. It could be other places but on a '96 V6 it was on the driver side of the intake area about mid engine and on a '97 5.0 V8 it was on the rear of the passenger side intake plenum near the transmission dip stick. If you're careful you can drill the rivets out of the metal one and clean the accumulated debrise from the sensor diaphram area and the vacuum line ports then pop rivet it back together to fix it. I've not opened a plastic one so no idea if those can be cleaned out.
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robask
Explorer, Sport Trac, Mountaineer & Aviator
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Oct 24, 2001 11:20 PM
