Scotsman828

Here's the problem I'm dealing with, I spent alot of money and did alot of work to my 97 Jimmy to get it running decent again. But still had the problem with rich mix in bank 1 and bank 2, IAC would never seem to find a proper setting, so idle was all over the place, if I put the tranny in neutal while coasting the idle would actually increase with while coasting downhill. Shouldn't the idle be at 850rpm if coasting? It would actually run better when the Check Engine light was on, I guess the computor went into the default setting when light came on. Now my EGR is sticking because of the rich mix in both banks and manifold is total sooted up inside. What I'd like to know, would it be possible to solder in a resistor on the O2 leads so the computor will read a proper mix? I'm sick of paying out $60 /O2 sensor just to replace it again in 6 months. It has 4 O2 sensors.
I'll take care of the EGR problem by putting in a blocker plate so my intake won't soot up anymore. Thanks in advance!

Scotsman828

Anyone?

technical

Sounds like a bad vacuum leak. Don't try hacking the O2's to fool the computer. Find out what's wrong and fix that. Do you have a vacuum gauge?

Scotsman828

I don't have a vacuum leak, I've sprayed every vac connection with starting fluid and the engine idle never changed.
I'm getting sick of all this computor crap! It's like Microsoft designed the damn thing, why the hell does it need 4 O2 sensors. Shouldn't one in front and one behind the Cat be enough. I miss my old 92 Jimmy with TBI. I want a car that is dependable, a person should not have to be a freakin' rocket scientist to keep it running. If it keeps giving me headaches I'm gonna buy a Edlebrock intake and put carb on it and change the distibuter to an Accel. That way I can rid the engine of all the B.S. sensors and get control over my engine again.

Scotsman828

BTW, what would be the danger of fooling the computor with resistors soldered into the O2 leads so it reads a perfect mix?

WAHUSKER

iTrader: (4)

You can put sims in for the back sensors, but the PCM reads the front ones to adjust the a/f mix. Have you tried cleaning the resistors on your MAF yet? Sometimes they get fouled (like with oil off a K&N filter) & then your car will run like you describe. Just a thought.

Scotsman828

I have stock intake. The MAF is descreened. I'll check the wires on the MAF for debree. Where can I get the sims for the rear O2s? I'm at my wits end. Thanks guys!

technical

There's a good chance descreening the MAF is where the problem is. Basically similar to the vacuum leak, but instead of a mechanical issue fooling the computer it's an eletronic issue. How long have you been running the descreened MAF?

Scotsman828

Finally found the problem, the EGR was completely stuck open. I'm getting to much carbon deposits from the rich mix, still not sure what is causing that problem. I unstuck the EGR and just put a blocker plate under it, cleared my trouble codes and let the engine run while the code reader was in trip mode and didn't pull anymore codes. Engine is running fine now. Thanks for the suggestions guys, I get frustrated cause the goverment and car makers are trying to make cars too difficult for the average shadetree mechanic to work on. Thanks again, happy programming guys.