Over time, you can expect the throttle body installed on your Chevy Trailblazer 4.2-liter engine to retain residue form road grime and from the gas you put into the gas tank. This is especially true if you use gas with Ethanol in it. A quick cleaning of the throttle body will ensure your engine receives the appropriate amount of air and fuel to keep your engine running.
Loosen the cam screw on the band clamp that secures the air intake hose to the front of the throttle body with a screwdriver. Pull the intake hose off the throttle body to expose the throttle body bore. The throttle body is on the front of the intake manifold on top of the engine. The air intake hose is black and about 5 inches in diameter, making it easy to find the throttle body.
Spray the outside of the throttle body housing with throttle body cleaner and wipe it off with a clean towel. Depending on how dirty the throttle body is, it may require several repeats of spraying and wiping.
Spray the throttle body linkage on the right side of the throttle body. Do not wipe off the fluid; let it air dry. This will prevent the possibility of damaging the linkage with the towel.
Turn on the Trailblazer and spray the inside of the bore with the throttle body cleaner. As you spray, pull back on the throttle body linkage. Be prepared, as the engine will rev when you do this. Repeat this process until the walls inside the bore and the butterfly valve inside the bore are clean.
Place the air intake hose onto the throttle body bore and secure it by tightening the cam screw on the band clamp.
