GM 90537679
Exhaust Manifold

The first step for Exhaust Manifold replacement of a 2.2l (L61) starts with Battery Cable negation then followed by Exhaust Manifold heat shield disconnection. When working on a 2.2l (L61) you need to raise the vehicle and remove the Oxygen Sensor first. Keep the exhaust flex decoupler free from more than 3 degrees of directional bending to avoid damage. First remove the pipe to manifold nuts then use downward and backward motion on the Exhaust Pipe to separate it from the Exhaust Manifold. First lower the vehicle and afterward remove the Exhaust Manifold to cylinder head nuts before extracting the Exhaust Manifold. You should clean every surface that needs to be sealed before you put on the new Exhaust Manifold Gasket and attach the Exhaust Manifold to the cylinder head. Use the specified tightening sequence to install new exhaust nuts before torquing them to 13 nm (115 inch lbs.). The vehicle raising process includes new Exhaust Manifold with flex coupler gasket installation to position the flex coupler correctly against the Exhaust Manifold. Install new exhaust nuts and retaining nuts to secure the manifold with the flex decoupler before torquing them to 30 nm (22 ft. Lbs.). Reinstall the Oxygen Sensor and the Exhaust Manifold heat shield following the installation of new exhaust nuts so that the bolts achieve torque to 25 nm (18 ft. Lbs.). Reconnect the negative Battery Cable as the final step of the process.

Starting the replacement of the Exhaust Manifold requires disconnecting the Battery Cable and removing the Exhaust Manifold heat shield. Begin by taking off the Oxygen Sensor followed by lifting up and suspending the vehicle. A bend of less than 3 degrees in any direction applied to the exhaust fox decoupler remains safe for operation. The Exhaust Pipe should be separated from the Exhaust Manifold by removing its attaching nuts followed by pulling down then back on the Exhaust Pipe. First modify the vehicle height before dismounting the Exhaust Manifold to cylinder head nuts and finally taking out the Exhaust Manifold. Thorough cleaning operations should be performed on every sealing surface before putting an Exhaust Manifold Gasket together with its cylinder head. Use new exhaust nuts together with retaining nuts for installation and torque them to 18 nm consistent with the specified sequence. After raising the car use a new Exhaust Manifold to flex coupler gasket to position the flex coupler at the Exhaust Manifold location. The retaining nuts should normalize to 30 nm (22 ft. Lbs.) during the process of securing the manifold to the flex decoupler. You should first lower the vehicle to reinstall the Oxygen Sensor after which you can attach the Exhaust Manifold heat shield before securing the bolts at 25 nm (18 ft. Lbs.). Complete the task by reestablishing the connection to the negative battery terminal.

Detach the heated oxygen sensor (HO2S) connector position assurance (CPA) retainer and disconnect the engine harness electrical connector from the HO2S, then remove the HO2S clip from the thermostat housing.

Place the exhaust manifold gasket and then the exhaust manifold, ensuring to tighten the exhaust manifold nuts to 13 Nm (115 inch lbs.).

Take care not to bend the exhaust flex decoupler more than 3 degrees in any direction, as excessive movement will cause damage.

The exhaust manifold gasket, which should also be discarded.