A hole in the exhaust wouldn't set a cylinder misfire. Did you check the coilpack for any white powdery substance? Have your checked and/or replaced the spark plugs and wires? Are you burning off coolant? Do you get white smoke from your exhaust? Are there bubbles in the reservoir? Is there oil on your spark plugs?
coil clean, tests out good...new plugs, wires...head gaskets done...no coolant level issues or smoke issues. Now just a tiny little sputter...every once in a great while.... went off came back on this am.... seems like @ thruway speeds the mis fire happens...because I dont feel it at all. cel comes on...on the thruway?!!! who knows right now...its driving me insane. Only cyl. 3 or 4.... maybe coil when hot...shorts ? I dont know
did anyone find a fix for this just got my headgaskets done.. Heads rebuilt with delta 1500 grind in them every two to three days i get 303 and 304 code everytime and it only seems at start in the morning doesnt happen again when i clear it til 2-3 days later!!