The spark plug is a representative device that will help the flow of electrical power from an ignition system up to the fuel inside the combustion engine. Basically, the spark plug is composed of a combination of a metal shell screwed into the cylinder head of the engine and a central electrode that goes into the cylinder. When the ignition system creates a spark, this will be able to jump across a narrow gap existing amid the electrode and the metal shell. This then will lead to the process of igniting the air-fuel combination inside the combustion chamber.