This is best checked by a pro. It could be a myriad of things it can be anything from a bad ground to a bad distributor to a bad pcm. You shouldn't go replacing things to fix it when it may just be a bad vent to the distributor. This has to be diagnosed using the freeze frame function on a scan tool to try to weed it out.
Sunday, August 8th, 2010 AT 8:07 PM