Need DPFE sensor, new or used?

[Hardwareman]

I just found out yesterday that my DPFE sensor is bad and wanted to know if I could get away with getting a used one or is something I should buy new. Thanks




Allen

 

[MAKG]

Can you test it in the field?

If yes, used is fine. If no, don't go there.

 

[Hardwareman]

OK, thanks Mike.

Don't know wether or not I can take a battery in there with me. That's what I need to test it. Maybe I'll look for a vehicle that was driving until it was hit....haha




Allen

 

[Destroyer000]

how do you test these with a battery?

 

[Hardwareman]

how do you test these with a battery?

According to my Haynes manual you have to test the voltage first from wiring harness connector with the KOEO. You need to have between 4.0-6.0 volts with 5.0 volts being ideal. Guess what.......that's what I had! If your voltage is not within specs the problem most likely lies in the PCM!

To check the sensor you need to use jumper wires. You have to ground one of the pins and apply battery voltage to the other. Lightly blow air through the DPFE (egr regulator) and verify that air flows through it. Replace the DPFE if this does not occur. Guess what......can't blow through mine!

It does'nt state exactly which pins so I tried it a variety of different ways, the first being the DPFE signal wire to voltage and the other (tried both) to ground. Mine would not open, and being closed is normal for this sensor until the PCM requires it to open.




Allen

 

[dusto2]

i would say just buy new by the time you look for a good one you have spent alot of your own personal time, they dont really cost that much anyway

 

[almostclueless]

1. Haynes manuals fellate barnyard animals. The Ford shop manuals instructs the tech to connect a vacuum hand pump to one connection and check the output voltage change per specs.

2. From all I've read about exhaust crap killing the solid state pressure sensor in these things, I'd move straight to a motorcraft replacement.

 

[Hardwareman]

Ok, well I just went out and bought a new one. Not a MotorCraft though, did'nt have enough for it. This one has a 2 year warranty anyhow and this is the original one that I replaced so hopefully it will last that long again.

I started the engine up afterwards and it was still a little rough but not as rough as before. It started smoothing out after a bit, but I only had it running a total of like 2-3 minutes. Could need to relearn though as well cause I had the battery disconnected too. I'm going to take it out here in about a half hour or so.........OH GOD I hope this was it.




Allen

 

[MAKG]

It will need to relearn because it had a bad sensor. It will misuse the EGR until it gets right.

Disconnecting the PCM was the right thing to do. That's the shortest time to adapt.

OBD-II technically needs a "drive cycle" (which includes warming up!) to get it right.

 

[Hardwareman]

Mike, could it take more then 1 "drive cycle" to re-learn?

I just got back from driving it around town, and believe me it's a lot better then it was but if I listen "real careful" I can "sometimes" hear a slight (miss?) out of the tailpipe at idle. It's perfect while driving and it's not always there. I also just reinstalled my transmission again because I was lazy and did'nt put a new pilot bearing in it when I swapped motors and there was a major drag when shifting into 2nd & 4th. I also went ahead and threw a new throwout bearing in it while I was there.........lesson learned!

Needless to say, the transmission is shifting "like new", and I took Mutant Pony's advice and put motor oil in it with some "Lucas Oil Additive". The Ranger feels GREAT now and drives better then she has in a while. I'm just still concerned with the slight miss (at idle) if that's what it is?

Still have the problem with the IAC though not increasing rpm's with the A/C. This is going to be a work in progress.




Allen

 

[LearjetMinako]

Could you enlight me some on what is a "DPFE" sensor? My brain doesn't work too well when its been crooked for 8hrs in 100 degrees weather.

 

[Hardwareman]

Could you enlight me some on what is a "DPFE" sensor? My brain doesn't work too well when its been crooked for 8hrs in 100 degrees weather.

It stands for "Differential Pressure Feedback Exhaust" sensor. It's a little box bolted somewhere to the engine usually, that has two lines feeding into the EGR tube and sends signals to the PCM so it can determine how much vaccum the selenoid should allow to the EGR valve. Then the EGR valve can open accordingly. When it malfunctions too much exhaust can enter the intake and cause misfiring, stumbling, and rough running conditions.

Nightmare if you ask me......haha




Allen

 

[LearjetMinako]

It stands for "Differential Pressure Feedback Exhaust" sensor. It's a little box bolted somewhere to the engine usually, that has two lines feeding into the EGR tube and sends signals to the PCM so it can determine how much vaccum the selenoid should allow to the EGR valve. Then the EGR valve can open accordingly. When it malfunctions too much exhaust can enter the intake and cause misfiring, stumbling, and rough running conditions.

Nightmare if you ask me......haha




Allen

Okay, I know exactly which part you are talking about. Thanks.