Just before my warrentee ran out I had a bad miss in one of the cylinders, followeed shortly thereafter by the "Check Engine" light. Dealership replaces coil pack and plug under warrentee.

Funny thing happened around 2x the warentee milage. I just started getting this miss in one of the cylinders.

Is there any way to easily test for the failed coil pack. Does anyone know the Ford Service # for it. Better still, is this even worth replaceing myself.