GM 91171190
Exhaust Manifold

The beginning of Exhaust Manifold service requires first checking the exhaust system for coolness to prevent burns along with disconnecting the Battery Cable. Rise the vehicle and maintain support while removing the two bolts from the front pipe along with the twc assembly if installed or the wu/twc assembly. The first service task requires users to disconnect the heated Oxygen Sensor (H02S 1) electrical connector while the sensor remains on the ground below the car. The next step is to remove the Exhaust Manifold heat shield's three bolts and afterward detach four bolts and three nuts and the engine hanger from the Exhaust Manifold. Disconnect the Exhaust Manifold Gasket which has been located on the Cylinder Head. Place a new Exhaust Manifold Gasket on the Cylinder Head after which you can install the Exhaust Manifold together with the engine hanger, four bolts and three nuts before tightening them to 23 nm (17 ft. Lbs.). The Exhaust Manifold heat shield needs to attach to the Exhaust Manifold via three bolts which should be tightened to 15 nm (11 ft. Lbs.). Install the front pipe/twc assembly or the warm up/twc part onto the Exhaust Manifold after applying a new seal by fastening two bolts to 45 nm (33 ft. Lbs.) torque. After lowering the vehicle, install the heated Oxygen Sensor (H02S 1) with proper torque of 40 to 50 nm (29 to 36 ft. Lbs.) before connecting its electrical connector and reattaching the negative Battery Cable. The examination should include a check for exhaust system gas leakage.