30530-RNA-A01 Knock Sensor - Overview. The 30530-RNA-A01 Knock Sensor is a critical component in Honda marine engine systems. It is designed to detect engine knocking or detonation, sending precise signals to the engine control module to adjust the engine timing and optimize performance. This sensor plays a pivotal role in maintaining your engine's smooth operation, preventing potential damage from improper combustion. Engineered to meet factory specifications and tolerances, the knock sensor en