(96 Cavalier Z24 2.4ltr) Rented a scanner. First scan gave me a MAP error, turns out I didn't attach the vacuume hose..woops. Fixed that and actually idles now with small sputter. Second scan now gives me the P0303 code, Cylinder 3 misfire detected. Going to start by swapping the coil packs to see if the misfire moves to a different cylinder. Plugs are all good as well as the boots. Anything else I should check to narrow down the cause of the problem? Personally, I believe it's the ECM but I want to exhaust all options befor going that route. Thanks

whats up man. yeah to solve your problem, i'm having the same issue. changing the coil pack should be good. as long as your spark plugs and spark plug wires are good. Also, to go along with that changing the ignition module and egr valve will help. At least, these are all the parts i'm about to change. good luck. let me know.

Hey, what you got there is a misfire in the number 3 cylinder. Could be a few different things. It might just be time for a tune up or the coil is taking a dump. At my shop we usually run into just needing to change spark plugs and boots or wires. Coils are one of the rarest things we replace. So I would say tune it up if you haven't done it within the last 50-70k miles. So new sparks plugs and boots. If it persists then start looking at the coil.