OEM Automotive Spark Plugs

Spark plugs provide a gap for the spark to jump. The spark ignites the compressed air fuel mixture in the cylinders. A metal conductor runs down the center of the plug surrounded by a ceramic insulator. The end of the conductor forms the positive electrode. On the end of the metal case is the ground electrode, it can be bent to make the right spark plug gap, which will vary depending on the kind of ignition system. Spark plugs should be checked when they misfire or have a rough idle, there's uneven power on acceleration and increased exhaust emissions.