Omnipower replacement knock sensors replace old, worn out, or broken factory knock sensors. Each sensor is made to factory specifications using the same internal microphone circuitry as the original. The knock sensor functions by listening to engine noise and vibration, and the ecu is programmed to recognize when the vibration deviates from what has been determined as normal. If the engine knock occurs, also known as pre-ignition or detonation, the noise level or vibration frequency of the engine increases dramatically. This in turn will show up as an increase in voltage in the knock sensor circuit, monitored by the ecu, and will cause the ecu to retard ignition timing until the noise frequency is back to normal. Faulty knock sensors can cause 2 types of problems. First a soft knock sensor (one that does not pick up enough sound) will not pull timing under dangerous pre-ignition conditions and can cause piston and ring breakage. Second is the loud (over amplifies the sound) condition which causes timing to be pulled when it's not necessary, causing poor fuel mileage and sluggish performance. Omnipower replacement knock sensors come with a lifetime warranty and help restore your vehicles performance to new. Fits These Vehicles:92-01 Integra GSR and Type-R, 94-97 Del Sol, 99-00 Civic Si.Fits These Engines:B16A, B16B, B17A, B18A, B18C.