sometimes when im driving ill come to a stop and my car will have a real eratic idle . 500 up tp 2000 and my service engine light will be on. ill park it, 5 minuts later ill go to start it and everything is fine? no engine light nothin. this happens like every other time i drive it? neone know what the F@@k is going on

 

possibly a bad idle air motor? Does the idle hang up at all as you come to a stop (like stay high or dip real low as you come to a stop like on the verge of stalling?) See if you can get that code to store..it probably has even with the engine light out...try pulling the code.

 

it bounces up and down and i just replaced the iac about 4 days ago
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the code i got the other day was a code 42 but after awhile when the engine light shut of there were no more problems

 

code 42 usually comes up after changing the timing (after unplugging your timing connector by the blower motor). However it in reality it is an est code (electronic spark timing) code. Check your igntion module under your distributor cap (the black rectangular thing that has two plugs on each side of it) and make sure your timing connector is plugged in (single wire pigtail, the wire is tan and black) Erractic timing jumps im sure could cause your erratic idle.