Idle problem when off gas

[Kevin_315]

My buddy has a 02 3800 procharged, and when he tries braking the cars idle goes to 500 then back to 1k and keeps repeating this process till he stops fully even has died a few times on him he said. I was told it had something to do with the idler or the Idle air control valve. Now the question is is it going to be the IAC or do I have to replace his whole throttel body? I was told that the ideler was part of the maf/throttel body and it all had to be replaced as one unit, in my book the IAC can be replaced alone but I dont know if this is the problem or not. Any help and advice would be helpfull, mind you this is ONLY happening when he lets off the gas.

[kcougar]

im just thinking, maybe the throttle position sensor? i know i need one. and on occasion my car will do that too

[Lyle A]

You can relace the IAC seperately on any car. Check for vacuum leaks first. Scan the PCM for codes.

[Kevin_315]

we had it scanned and i didnt write the codes but the guy said that 2 were it runnin rich and the other 2 were for idle and speed control. so its something with the idle being messed up (that was auto zone)

he had it scanned and it showed two codes for idle and speed control, and my buddy said that the guy at midus/dealership or where ever he took it said it was probably something to do with the throttle body or a sensor inside it. What exactly is the ideler a sensor? or like i said i know the IAC is in the throttle body, but they said it was a sensor around in there.

[kcougar]

like i said in my above post the throttle position sensor, it is located up by the TB. It also sounds alot like symptoms of a failing sensor.

[ragesk813]

my car was doing the same thing, changed the throttle position sensor...did nothing. i even changed all my 02s and nothing...im stumped

think maybe the IAC could be the problem?