GM 15744810
Catalytic Converter

The replacement of a Catalytic Converter on an a4wd vehicle requires protective goggles and gloves to safeguard against rust and sharp edges with a cool exhaust system before the installation process begins. Start the process by raising the vehicle and suspend the Catalytic Converter assembly. Start by disconnecting the 3 Oxygen Sensor electrical connections and removing the clips followed by breaking the Muffler flange bolts and the Exhaust Manifold studs on both right and left sides while disconnecting the collars. Remove the hanger assembly attached to the Catalytic Converter from both the Transfer Case and the Catalytic Converter before disassembling it from the Muffler and exhaust manifolds with caution toward the oxygen sensors' protection. Wrap the Catalytic Converter assembly by lowering its rear section to move it in the direction of the vehicle's rear then rotate it down behind the Transfer Case support crossmember before unclipping the oxygen sensors from their ports. Check that all exhaust system components match oem specifications for safe operation then verify alignment before tightening bolts or nuts. To make a proper connection between the Exhaust Pipe and Exhaust Manifold always replace damaged hangers brackets and clamps while using new nuts post-thread cleaning. Place the oxygen sensors at their designated spots on the Catalytic Converter assembly before raising and rotating the assembly to fit it correctly with the left Exhaust Pipe between the Torsion Bar and transmission. Attach the Catalytic Converter assembly to the Muffler assembly by installing a gasket and keeping the nuts on both sides loosely attached to Exhaust Manifold studs. Follow a sequence to tighten the Exhaust Manifold nuts at 53 nm (39 ft. Lbs.) and the hanger-to-Transfer Case bolts at 55 nm (41 ft. Lbs.) while torquing the assembly-to-muffler assembly nuts to 40 nm (30 ft. Lbs.). After restoring the Oxygen Sensor electrical connectors and removing the Catalytic Converter assembly support you should lower the vehicle.

Loosely install the collars and nuts onto the exhaust manifold studs on both sides, connect the catalytic converter assembly and gasket to the muffler assembly, and loosely install the nuts.