Attach the spark plug to a spark plug tester, then connect the tester to the ignition wire. Start the engine and observe the ...

How to test a spark plug Although this is something you can certainly leave up to the professionals, it’s also simple enough to do at home.

In this video, I show you how to test spark plugs and coils on any car, even if the spark plugs are recessed or hard to reach. Whether you're troubleshooting engine misfires, poor performance, or ...