ACDelco GM Original Equipment 213-3521 Ignition Knock (Detonation) Sensor Fits 2004 Chevrolet Silverado 1500
 
GM Original Equipment™ Ignition Knock Sensor (213-3521) by ACDelco®. If you want to restore the original performance of your vehicle's ignition system, this product is what you need. Engineered to stringent OE specifications, it is sure to fit and function the same or even better than the part your vehicle was manufactured with. This product is made from premium materials to serve you for years to come.