In the case of four cylinder vehicles, the knock sensor is situated in the vicinity of the engine block at the side of the intake manifold. First remove the connect the cable on the negative terminal of the battery then take off the intake manifold. Then, pull the connector, unscrew and remove the sensor mounting bolt, and at last, take out the knock sensor. On V6 models, the knock sensors are installed below the engine in the valley between the heads and needs the lower intake manifold to be pulled out. However, you should begin the procedure by either loosening the cable from the negative terminal of the battery or by removing both the upper and lower intake manifolds. Remove the knock sensors electrical connectors and the wire harness retainers from the engine block and unscrew and take off the sensors. Removal is the process that is the opposite of installation, checking that the knock sensor mounting bolts are tight to the torque setting.