The camshaft position sensor determines the position of the cylinder for sequential fuel injection signals to each cylinder and is mounted on the cylinder head near the intake runner for cylinder no. 4, secured with one bolt. A problem in the camshaft sensor circuit will set a diagnostic trouble code. Ensure the ignition key is in the OFF position, then remove the engine cover. Disconnect the harness connector, remove the mounting bolt, and take out the camshaft sensor from the cylinder head. Installation is the reverse of removal, using a new O-ring lightly coated with engine oil.