1994 EGR Pressure Feedback Sensor (AKA DFPE)

[Cheddar_Dan]

Hey All!

Might you know if there should be some noticeable response when unplugging EGR pressure feedback sensor while engine running? Mine shows no difference plugged in or not and I'm wondering if that means anything??????????

THANKS!
.cd

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[mcfixstuff]

Same, would love to know from someone who is familiar with EGR systems on the explorer

 

[BrooklynBay]

Those parts are easily damaged by moisture getting into the vacuum system. Maybe the part isn't working since unplugging a sensor usually throws a code. Do you have a check engine light or any codes? Check this link for more information: How to Diagnose a DPFE Sensor Problem

 

[Turdle]

It's only referenced when egr is called for. Does nothing but monitor the pressure difference between 2 orifices when egr valve is opened. If low or high flow is detected, then it will throw a code. Hope this helps.

 

[Cheddar_Dan]

It's only referenced when egr is called for. Does nothing but monitor the pressure difference between 2 orifices when egr valve is opened. If low or high flow is detected, then it will throw a code. Hope this helps.

Thanks! I'll have to let that sink in my old brain. ...OT this morning, oddly, no CEL or running rich for 8-9 miles. I have moody truck! LOL!

 

[410Fortune]

Some codes take many drive cycles before they are a hard code and show a light
Simply unplugging the dpfe (especially in a 94 obd1) will not set an immediate fault
The computer first needs to command egr to open then has to see nothing from the dpfe possibly more than once before it will set a code. Simply unplugging it for 8 miles you may or may not get a light…. In this case it looks like not

 

[Cheddar_Dan]

UPDATE: DPFE replaced. No difference. Once started engine is oxygen starved.

 

[410Fortune]

Oxygen starved? Running rich?

What is she doing exactly? How
Many miles on the 4.0?

 

[Cheddar_Dan]

Engine starts easily and normally but instantly idles rough at lower than normal RPM. After 10 seconds CEL appears. Haven't run codes since I can't find my tester. -is drivable but gas mileage is down to about 10-11 mpg.
This morning CEL went *way* while driving and engine ran ok *after* driving 8 miles with illuminated CEL and issue.
BTW If I start the engine and immediately pull a cap off of the vacuum cluster I get a smooth idle.
Explorer has 220k miles under her belt.
Best!
.cd

 

[410Fortune]

Need the code

Can be checked w a paper
Clip

 

[Cheddar_Dan]

Need the code

Can be checked w a paper
Clip

Thanks! I forgot about that!!! (wondering what else I have forgotten?!?!!?) LOL~!

 

[Cheddar_Dan]

Update:. Engine runs normal (or, more normal) with idle air control valve removed and it's intake holes closed off.