First of all if you identified a problem with a spark plug wire it should be pretty obvious that's the place to start. Bad connections on spark plug wires commonly cause misfiring, stalling, and backfiring. Worn spark plugs can cause similar symptoms.
If the Check Engine light has turned on there will be a diagnostic fault code stored in the Engine Computer. That code will indicate the circuit or system that needs further diagnosis. Even if the light hasn't turned on there could be a code in memory.
Monday, April 1st, 2013 AT 7:26 AM