If there is a component on a Pontiac engine that gets little or no thought, it's the spark plug. We refuse to spend much money or time on them, but unless your Pontiac is powered by a GM diesel, the ...

1 Spark plugs with light tan or gray color deposits usually indicate a sound engine and ignition system. Plugs within this color range can have normal electrode wear of about. 005-to. 008-inch, which ...