Car has 145K on it and have just replaced the spark plugs, ignition coils--all 6, ignition coil female connectors, ran two bottles of injector cleaner and at full operating temp and left to idle for 5 mins or more, the idle will become very rough and give a check engine light and error code 302. I am being told this is cylinder 2 misfire. Is this true and thoughts to fix?? Have spent over $500 so far and no closer and don't want to keep replacing parts that don't need to be. Ignition control module has been the nxt item thought to be the culprit. At $68 isn't too bad, but this car has two and if cylinder 2 is the problem, which one of the modules would it be?? Checked the FAQ's and didn't see a 302 in there.