The knock sensor is located under the intake manifold, on top of the engine block. Begin by removing the intake manifold, followed by the fuel rail assembly. Although Acura suggests removing the injector base to access the knock sensor, it is possible to reach it using the right tools, such as a deep socket and a flexible extension, without removing the lower intake manifold. If access proves difficult, then proceed to remove the lower intake manifold. Next, disconnect the electrical connector from the knock sensor by depressing the release button with a long slotted screwdriver and pulling the connector straight up with long needle-nose pliers. To remove the knock sensor, use a deep socket, a universal joint, and an extension. If the sensor has an O-ring, discard the old one and install a new one. Installation follows the reverse order of removal, ensuring the knock sensor is tightened to the specified torque.