The Facet Ignition Knock Sensor - 93163 is a sensor designed to detect engine knock or detonation in a vehicle's ignition system. It works by monitoring the vibrations in the engine and sending signals to the engine control unit to adjust the ignition timing and prevent damage to the engine. This sensor is crucial for maintaining the performance and longevity of the engine. It is compatible with various makes and models of vehicles and is a reliable and durable component for any ignition system.