Chevrolet introduced the Trailblazer as a separate vehicle in 2002. Prior to 2002 the Trailblazer label was attached to the Blazer model as a top trim level designation. Chevrolet only offered 4.2-liter in-line six-cylinder engine for the 2002 Trailblazer. Optional 5.3- and 6.0-liter V-8 engines followed in 2003 and 2006. The throttle body controls the amount of air that enters the engine by movement of a throttle plate, similar to the butterfly valves on a carburetor.
Instructions
Removal
- 1
Park the Trailblazer on a level surface and set the parking brake.
2Remove the intake resonator by disconnecting the intake air temperature sensor electrical connector. Loosen the clamps on each side of the resonator that connect the intake duct and throttle body to the resonator with a flat-head screwdriver.
3Disconnect the pressure regulator vacuum hose from the resonator. Remove the two bolts from the resonator with a ratchet and socket. Lift up the resonator and disconnect the PCV hose from the valve cover. Remove the resonator.
4Squeeze the tab on the electrical connector on the throttle body and disconnect it. Remove the canister purge line from the throttle body. Remove the four attaching bolts from the throttle body with a ratchet and socket. Remove the throttle body.
5Remove the old gasket from the throttle body and intake manifold. Wipe the surfaces with a shop rag. Do not use a scraper or solvent.
Installation
- 6
Mount the new throttle body with a new gasket onto the intake manifold. Install the bolts and working in a crisscross pattern, use an inch-pound torque wrench and socket to torque the bolts to 80 inch-pounds.
7Connect the canister purge line and electrical connector to the throttle body.
8Lower the resonator into position and reconnect the PVC hose to the valve cover. Attach the air hoses to the throttle body and resonator. Install and tighten the resonator bolts. Connect the pressure regulator hose and air temperature electrical connector. Tighten the hose clamps at the resonator and throttle body.
