droped off my son started car and it sounded crap.. like a subaru, drove it a bit, not much loss of power but sounded terrible, stoped and turn off, started again and still the same!! drove it a bit more then it jumped into life as it should drive, done a bit of reading so im guesing its the coil packs

..... or could it be somthing else? oh and my service light has just came on, routine one.