88 Iroc Z w/305 TPI, auto trans. Check engine light comes on sometimes when I start the car. If I try and pull a code or take it to parts store and hook up a code reader I get nothing...I find that if I get in the car and turn the key for a few seconds before I start the car I generally do not get the check engine light...I have changed plugs, O2 sensor, PCV, removed the K&N filters, could it be my MAF sensor needs replacing? When I do get the check engine light the car runs on the road fine but has a minor rough idle and when I get to a stop sign/light the idle is way down and the car may die... I do not get a check engine light all the time just on occasion but it is frustrating and it only started happening within the last few months. Any insight??

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