had a misfire the other day, opened the bonnet to find the cylinder 3 ht lead arcing on the coil pack, put a strip of rubber between to the two, cleared the code and ordered a new coil pack. new one came so got it replaced, car was running better then ever but as soon as i started going down the road and the light came back on, comes up as coil pack malfunction but car is running great. any ideas?