So I was driving my car tonight kinda hard (not that bad) on the highway, my Rpms were in the 3500-4000 range for a good amount of time.. After i get off the highway the car is running rough, sounds like a wrx. I know people on this site say a car sounding like a WRX is most likely the coil packs.
My question is... What causes the coil packs to go? Is it just coincidence that they went after I was getting on the car a little? And how can I determine which coil pack out of the four is the bad one or one(s).