GM 15747730
Catalytic Converter

Vehicle elevation and transmission support must be removed before proceeding with a Catalytic Converter replacement. The technical process starts with disconnecting both oxygen sensors (02S) along with heated Oxygen Sensor (H02S) from the wiring harness using protective goggles and gloves. One Catalytic Converter replacement requires both valves active so a secondary converter needs removal unless replacing both converters simultaneously. The removal of both units becomes necessary when replacing the left Catalytic Converter. The next step requires removal of all nuts and seals which attach the Catalytic Converter pipes to exhaust manifolds. Nonetheless, single Catalytic Converter pipes require removing two retaining nuts that lead to two-bolt or three-bolt flange configurations. Lift the Catalytic Converter pipe flange gasket before removing the pipe from the vehicle. When your vehicle has two Catalytic Converter pipes you must first loosen the front Muffler clamp securing the right catalyst before taking out that pipe from the Muffler unit. After untightening the left Catalytic Converter pipe retaining nuts and gasket from the Muffler flange connection you must remove the left Catalytic Converter pipe. Catalytic Converter replacement requires that you remove all necessary oxygen sensors from the system. Install the oxygen sensors according to the original protocol but only proceed when removal was necessary. When using the dual installation method install the left Catalytic Converter with its gasket to the Muffler flange before tightening the left Catalytic Converter nuts to the Muffler. After installing the right Catalytic Converter inside the Muffler use the clamp to fasten it down but do not apply any torque. A standalone Catalytic Converter pipe needs fresh gasket installation between the Muffler flange while avoiding flange nut tightening. Place a new seal onto the exhaust manifolds before installing the Catalytic Converter pipes and then tighten the retaining nuts to 65 nm (48 ft. Lbs.). Apply proper exhaust alignment while tightening right Catalytic Converter clamps to 54 nm (40 ft. Lbs.) and natur stall nuts on the Catalytic Converter-muffler connection to 48 nm (35 ft. Lbs.). After reattaching the Oxygen Sensor (02S) electrical connection and reinstalling the transmission support check that the exhaust system shows proper clearance and all components achieve proper alignment before lowering the vehicle.

To service and repair the Catalytic Converter, one has to first lift the vehicle. Remove the h02s heated Oxygen Sensor from the Catalytic Converter pipe with transmission support ensuring the protective goggles and gloves have been worn. Knull the heated Oxygen Sensor (H02S) electrical connections from the Catalytic Converter pipe. But disconnect the transmission support of the sensor. Thirdly, unclasp the nuts and seals holding the catalytic pipe to exhaust manifolds; this is followed by the nuts on the catalytic pipe to the Muffler; then extract the Catalytic Converter from the vehicle. If it is needed; then take off the oxygen sensors. For installation, start with oxygen sensors installation if required, shift catalytic pipe to the vehicle. Mount the new retaining nuts and gasket on the front part of the Muffler, but do not tighten them. Replace the new seals, nuts and exhaust pipe flange to the Exhaust Manifold and tighten exhaust pipe flange to the Exhaust Manifold nuts to 65 nm (48 ft. Lbs) and the Catalytic Converter to Muffler retaining nuts to 48 nm (35 ft. Lbs). Reconnect the transmission support h02s electrical connection, and then reinstall it. Lastly, check the exhaust system for sufficient clearance and the alignment of all compounds before lowering the car.

Tighten to 65 Nm (48 ft. lbs.).

Install the new retaining nuts and gasket to the exhaust flange without tightening.

Install the pipe with a new gasket to the muffler flange without tightening the flange nuts.