my s4 has a slight miss when on idle. it also seems to do it when driving slightly hard at about 3k rpm. my thots are its a coil pack on the way out but was wondering if anyone had any input. it doesnt always do it but when it does it is a regular miss and recon its only one cylinder. altho now and again it seems like it is more than one. i think it does it mostley when the car has been for a run, stoped for a period then started which leads me to the idea that the heat from the engine is soaking up to the coil pac and breaking down the coil. i cannot be sure.i dont know if the mis at 3k is related but had the idea that because it is around boost that it was a sticky re-circ valve causing a low flow/air stall across the MAF. i dont know if re-circ valves are prone to failure but this a symilar problem/cause my brother had with is 300zx. what is the best way to find out what cylinder has the misfire. i thought about getting a vag-com but would this tell me if a certain cylinder has a misfire. also do you know if i could measure the resistance of the coil packs to see if there is a differance between them thus telling me if one is breaking down. thanks in advance, any input will be appreciated.