2000 GMC C3500 Oxygen Sensor

You should remove the intake air resonator from the Throttle Body, and inspect the throttle body bore and the throttle valve plate for deposits, clean the throttle body bore and the throttle valve plate using a clean shop towel with GM Top Engine Cleaner, P/N 1052626 or AC-Delco Carburetor Tune-Up Conditioner, P/N X66-P, or an equivalent product, remove and disassemble the throttle body for cleaning if the deposits are excessive. After disassembly, you should clean the throttle body using a part cleaning brush, assemble and install the throttle body if previously done, and install the intake air resonator.

You should open the hood, raise the vehicle, remove the oil pan drain plug and drain the engine oil into a suitable container, remove the Oil Filter from the engine block and clean the drain plug and oil filter sealing surfaces.

You should install the Spark Plug Wires at the Distributor, install the spark plug wire to each spark plug and inspect the wires for proper installation.