GM 12569057
Exhaust Manifold

The first step for replacing the left Exhaust Manifold includes disconnecting the breather tube at the air cleaner outlet duct followed by removing the air cleaner outlet duct retaining wingnut then separating the iat sensor harness connector. After disconnecting the Throttle Body from the air cleaner outlet duct users must remove the intermediate Steering Shaft and disconnect the engine coolant temperature sensor wiring connector. The service technician needs to eliminate the radiator inlet hose support bracket and nut followed by raising the vehicle. Drop the vehicle by the Exhaust Pipe from the Exhaust Manifold before moving on. On the front side move the tire to gain access to bolts holding the rear Exhaust Manifold while pulling out the fender wheelhouse extension. Obtain access to the spark plugs through the wheelhouse opening by rotating each wire boot half a turn then pulling it outward. Lower the vehicle after removing bolts from the Exhaust Manifold and stud. Finally, you can take the Exhaust Manifold together with Spark Plug wire shields off from the engine. Gather and throw away the aged Exhaust Manifold gaskets followed by cleaning all surfaces where gaskets will rest. To install the Exhaust Manifold position the stud in the front hole while the gasket tabs maintain position of the bolts. For installation insert the Exhaust Manifold through the wheelhouse opening after raising the vehicle while positioning it by the engine from under the hood. Before installing the Spark Plug wire shields users should apply threadlock preparation gm p/n 1234,5493 (Canadian P/N 10953488) to Exhaust Manifold bolt threads and stud threads if they are using reinstalled fasteners. The Exhaust Manifold bolts and stud will receive initial torque of 15 nm (11 ft. Lbs.) before receiving final torque of 30 nm (22 ft. Lbs.). Beginning with Spark Plug wire installation onto retainer points and spark plugs, move to the front tire and fender wheelhouse extension after placement. The Exhaust Pipe needs to be joined to the Exhaust Manifold before lowering the vehicle in order to connect the ect sensor electrical connector. First position the radiator inlet hose support bracket along with its nut before tightening them to 36 nm (27 ft. Lbs.) and lastly attach the intermediate Steering Shaft to the vehicle. Handle the maf sensor with care while installing it by avoiding exposure to drops or screen and sensing element damage and apply a small amount of soap-based solution to help with mounting. Lastly finish the process by installing the air cleaner outlet duct onto the Throttle Body and maf sensor and connect the iat sensor harness connector as well as tighten the duct with its retaining wingnut before reattaching the breather tube.

Raise the vehicle and disconnect the exhaust pipe from the exhaust manifold before lowering the vehicle again.