Description: The Honda Knock Sensor (30530-PPL-A01) is a factory-spec ignition knock sensor for 2002–2011 Honda models, covering 2.4L Element, CR-V, and Accord, plus 2.0L Civic. Mounted on the engine block, it detects detonation vibration and signals the ECM to retard ignition timing, protecting the engine from combustion damage. A genuine Honda OEM sensor built to original sensitivity and thread specifications.