Alright you guys have helped me in the past. And hypertech are no help at all 1994 trans am cold idle super low when check engine light comes on (closed loop) idle goes up a little to high and irregular i tryed pulling out hypertech to check codes and chip says cannot communicate with computer call hypertech hypertec says chip does not interfear with checking codes. Well ive owned the car since 97 3rd engine 5th trans 3rd rearend and i remember when i first took the car for recall and they needed me to remove the chip guy said you can't check codes with chip installed.i have tryed and its a jumper wire and no codes just turns air pump on anyone have this proplem or point me in the right direction it has a lunati cam but it is slightly bigger than stock and lunati said it wont affect computer and it didnt the car is basically stock runs great wot just lousy idle i did plug egr valve any ideas thanks

 

get a real tune on it, hypertech is junk. talk to Solomon (lt1pcmtuning.com) and he can set you up. changing the cam and deleting the EGR will definitely affect the computer, CEL is probably because of the EGR delete.

also, use some punctuation in your posts. very tough to read/understand your run on sentences.

 

Hypertech is OK... but there are only limited values u can change with any hand help programmer... I'd look into updating ur computer to a 96-97 ECM, and change the harness so u can go OBD2... and pull codes if u need them.

The other thing I would suggest is idle air control valve may not be functioning.... so it's causing crappy low idle... 93-95 ECM is dead... upgrade... and things become a hell of lot nicer...

 

completely unnecessary to do, would be a waste of time and money to swap over to obdII for what the OP needs. just send it out for a mail order tune (soloman, PCMforless, etc.), or if you have someone locally that can dyno tune it do that.

 

^^ Exactly, why in the heck would you want to go thru all that trouble of changing a wire harness just for a low idle, makes no sense...

 

I need help with a high idle problem on my 94 Impala..... I don't know how to use this forum to post something......
It's got a high idle when the car is warmed up or just starting, I've read a lot of forums and tried some things that have been suggested. It slams into gear and shifts hard from 1-2nd. I did a test that I saw was suggested on another forum where you have the car running and then you un plug the IAC and after that you turn the car off plug it back in and start it and it will bring the idle down and it did but it creeps back up if I leave it plugged in.

I have replaced the IAC the TPS the coolant temp sensor I have checked for vacuum leaks with carb cleaner or TB cleaner and fixed the leaks that were needed, I've checked for exhaust leaks with a sniffer, I've checked the throttle blades and they are working properly not catching and the screw is not touching to keep them open, I've cleaned the TB and MAF, I've checked power to the plugs for the TPS and IAC, I've ran the car at night to look for arcing and there's none..... I'm sure there's a couple things I'm forgetting but I'm at a loss, I haven't had the car scanned yet but I need the get this fixed before I do anything else.... I am doing cam and heads after I get this all figured out and having Solomon tune the car for that..... Also the egr isn't sticking or stuck. The car seems to stumble a little but there is no loss of power at WOT or anywhere between