The gap between the center and side electrodes needs to be an exact distance across; otherwise, your plugs won't fire efficiently.

Follow these steps to remove each spark plug: 1. Gently grasp a spark plug wire by the boot (the place where it connects to the spark plug), twist it, and pull it straight out. Never yank on the ...

Car Care: Take cars that misfire to a repair shop, where their spark plugs and ignition boots should be checked.

To test the operation of both the ignition coil and the spark plug, connect the tester between the spark plug boot and the spark plug. Then start the engine and watch the tester window.

Most commonly applied on spark plug boots, lightbulbs, and battery terminals, dielectric grease is, in theory, a protectant like car wax.

Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head.