I have a 1994 3.4L Camaro. I have been getting the SES light for a while now, only when I slow down from highway cruising speed and it stays on for a while. Anyway, I took it in to the Chevy dealer to have them scan the codes and they told me that it was the EGR and that it was giving "Code 77 - #3 Cylinder Inoperative." That's what's on my bill for them scanning the codes.

Anyway I went ahead and spent the 170$ for the new EGR, cleaned the tube from the EGR to the intake and replaced with the new EGR. I am still getting the light, and it's frustrating.

I am wanting to sell my car in the very new future since I'm gonna be getting a new truck and would like to correct this because I don't want to sell a sharp looking car that drives great but has the stupid light on.

Has anyone else been given this Code 77 by anyone before? Would that code just happen to still be in the car's computer. Would that have to be cleared out after the new EGR was put in? What else might be causing this since I replaced the EGR and cleaned the recirc tube? Any ideas would be appreciated; it's frustrating as hell.

Brian

 

Welcome to my world. i have spent a lot of time and money and nothing has worked permenently. I am frustrated...I even have anew engine and egr and no improvement.

 

After driving 50 or so miles with the new EGR, the computer should "see" that the problem is gone and clear. Though you may need to have it cleared.

Take it back to whoever worked on it for you...they should have cleared it.

 

Actually what seems to happen is that I clear the code and for about 50-100 miles it is good...then here comes tha damn egr solenoid 2 and 3 again.

 

you might have to try cleaning the passageways in the intake itself. sorry i dunno off hand but your EGR is the digital 3 selinoid one correct? one thing you can do it unplug the connector. take a hot feed onto the valve and then a ground feed to each of the selinoids to triger them one by one as the car is running and listen for an RPM drop. gimme a sec and I will post what wires to connect to.



ok.. run a hot feed to the termonal that the brown wire on the connector attaches to, then a ground indevidualy on each of the other termonals. the red goes to number 3 the brown goes to number 2 the lite blue goes to number 1..

ok.. wait. this diagram is confusing. there are 2 brown wires achording to this so you would be better off testing witch wire has a hot feed

 

try disconnecting the positive side of your battery for about 15-20 mins and put it back on. this will clear the computer's system and it should recongize that the problem has been fixed. my ses light comes on all the time in my 94 but i haven't gotten the codes read. about how much does it normally cost? l8tr

 

Well, I took it to the Chevy dealer and they charged me 20 Bucks, Kinda high but at least I know what it was/still is. Damn light. Wish I knew how to just turn if off before I sell it this summer. The car runs perfectly fine and looks so good for a 94. Oh well.

b

 

I am not suggesting you do anything to help sell your car, b/c if you trade it in, more then likely the dealership will scan for codes....but I did cut the wire going to my SES light...just b/c the darn thing annoyed the heck out of me.

 

btw, our pcm notes the voltage/resistence in the wire to determine if the actual solenoid worked....I am not sure if replacing the wires and pug (to the egr only) work fix it....if you try this and it works...let me know.

 

The computer knows the EGR is opening in 2 ways depending on the type used. 1 way is by comparing acual position and desired position. anything more the a 10% different will set a code. the other way is my watching MAP changes when the EGR is comanded on. a blocked passage in the intake will set this cose due to the EGR being opned yet no change in MAP voltage is read. This is why the MAP should also be testing when you have an EGR code.


same thing for MAF codes for you 6er's that have them. it;s a rationality test thats used in both cases.

 

the 3.4 does not have a MAP...we have the iap...or somthing....right?

 

the 3.4 doesn;t have a MAF (mass air flow) but it does have a MAP (manifold absolute pressure) and an IAT (intake air temp)

 

Well where is the MAP sensor on my 94 3.4L? And if I would replace that, how hard is that to do and how expensive of a part is that?
Do those generally go bad after 150K Miles? What doesn't, right? That's about the milage I've got on the car now.

Like I said before, I had the codes scanned about a month and a half ago at the Chevy dealer and it was Code 77... cylinder 3 Inoperative. That's the only code they gave me. I disconnected the positive side of the battery for 30 minutes last week and the light stayed off for about 4 or 5 days and now it's back on today after slowing down from highway speed.

Anyway, any other ideas would be appreciated. I just want the car in clean running conditon (tho it drives and looks so good) without the Engine light because I'm going to be selling it soon when I get the new GMC Canyon in a couple months.

brian

 

I doubt it;s the MAP. I am betting on blocked passageways in the intake.