Misfire - Engine Miss
Remove Spark Plug Step 7 - When a cylinder(s) runs rich it will carbon foul the spark plug causing it to short circuit. Malfunctions for this condition include partially plugged fuel injector or catalytic converter, low compression, failed fuel pressure regulator and excessive fuel mixture.
Carbon Fouled Spark Plug Step 8 - A wet spark plug with gas or oil can mean a fuel injector is stuck open, fuel regulator has failed, no cylinder compression, broken piston oil control ring, blown head gasket or excessive leakage from the valve stem seals.
Spark Plug Fouled with Gas or Oil
Misadjusted Air Gap Step 10 - Using a proper spark plug with a correct air gap will help ensure operation of the ignition system.
Correct Spark Plug