Ok guys the car is a '97 6 spd. LT1 T/A. when i first start the car it runs fine for a couple of minutes then slowly starts misfiring badly, then A.I.R. pump turns on briefly(like 2 seconds) the idle will immediatly smooth out then slowly start doing the exact same thing over again. It probably does this every 2 mins. I replaced my EGR valve because of a EGR code. Still does the exact same thing, does not matter if its hot or cold. The car runs excellent other than at idle. Anyone ever experience a similar problem? Please post, Thanks

 

could that be an opti? I think it would of died already......maybe it's your computer, did your SES light go off after you replaced the EGR valve?

 

Usually with an opti the higher rpms go first before the low end. WOuld be very odd for it to misfire at idle and not at higher speeds.

What shape is everything else in? Plugs, wires? What about the throttle body, IAC, idle speed, etc. etc. etc.

Is there a tune or is the PCM stock?