CEL Still on after fix?

[JamesM007]

So I take the 94 limited to the dealer to read the codes. They wanted around $500 to fix. I ask what codes and they tell me 34 + 31. They say needs a DPFE sensor, a EGR valve, and a EVR selenoid.

Day 1: I changed the DPFE, light still on.

Day2: I changed the EGR valve, light still on.

Day 3: Today, I suppose I will go get a selenoid and change that as well.

My questions is this. Should I be cleaning out anything heavy duty with carb/throttle cleaner or something? I mean I did shoot some into the opening but nothing heavy, and besides, it looked not too dirty. Also, if changing the selenoid doesn't work, what might be the next step according to the codes my vehicle is sending out? By the way, I left the battery unhooked for about 3 hours while the engine cooled enough to replace the part hoping to reset the computer.

Thank you.

James.

 

[TPLYNCH]

Did you check the lines from the DPFE to the EGR? They get clogged w/crap and cause codes. Also make sure they are not cracked etc.

 

[MrShorty]

I don't know what others think, but I can't quite convince myself that a '94 should be putting out two digit codes. If it were me, I'd pull the codes again (It's pretty easy to do yourself: see www.dalidesign.com ) and make sure that those are the right codes. You would then know, too, if they are KOEO, continuous memory, or KOER. I realize the codes were pulled by the dealer and one would expect that the dealer should know how to pull the codes properly and whether or not a '94 can or cannot output two digit codes. But I always thought that an EEC-IV computer could put out either 2 or 3 digit codes (not both) and that the switch occured in '91-'92. I know that my '92 puts out three digit codes. Anyway, I'd try pulling the codes myself. It's easy, costs little or nothing (depending on if you have a piece of wire lying around and maybe an analog voltmeter), and would settle the question. That's my $0.02.
And if it turns out to be EGR codes still, then be sure to check the wiring and connectors and make sure that all the electrical connections and such are clean. It might also be wise to invest some time at the library looking up pinpoint tests and such to determine the exact cause for the codes.

 

[Glacier991]

I'm with MrShorty. His advice on this is excellent. Read em yourself and let us know. I may be able to forward the pinpoint tests from the factory manual for you.

Happy Exploring

Chris

 

[JamesM007]

I also thought that it was funny when the dealer told me a 2 digit code. I suppose I could try to hook a voltmeter to it as I do have one.

I also have an electronic version of the shop manual I could use to guide me through the hookup and lookup of the codes. I just thought it would be easier for the dealer to read them and I could easily replace the parts without having to take the time to learn it. Sounds like they blew me off with some BS codes. Figures.

I replaced the small hoses when I replaced the DPFE sensor.

Thanks everyone.

James.