The spark plugs are an important part of the ignition system. When you turn the ignition key (car's key) on, it causes the ignition coil to generate the spark which ignites the air-fuel mixture in the engine cylinders to start the engine. The number of spark plugs in the car is the same as the number of cylinders, although some vehicle manufacturers will use two spark plugs per cylinder. Over time, the spark plugs wear out and require replacement.
**Note: This is a service-only app Price varies by model