This has only happend a couple of times. After Ive been driving around for a while and the car is good and warm, I went into the store to get some stuff and after about 20 minutes I started the car up and it runs really rough for about a minute or two and then idles normally. Anyone have any idea's. It only happens if the car has been driving for 20min or longer.

Thanks

 

ignition coil or ICM heatsoak maybe