GM 19418926
Catalytic Converter

Starting the process of replacing the three-way Catalytic Converter requires vehicle elevation and proper support. Start by removing the oil pan skid plate if the vehicle has it and then proceed to remove the transmission crossmember. To perform a Catalytic Converter replacement, the heated oxygen (HO2S) sensors need removal from the system. Otherwise, disconnect their harness connectors. Remove the Exhaust Manifold pipe and discard the exhaust seals using bolt removal and nut loosening and loosening the band clamp bolt. The installation process starts by fitting new Exhaust Manifold seals followed by connecting the Catalytic Converter pipe to exhaust manifolds before torquing the nuts to 50 nm (37 lb ft). Fasten the three-way converter to the Muffler assembly with a clamp bolt torque of 44 nm (32 lb ft). Transmission crossmember installation should follow along with heated oxygen (HO2S) sensor fitting if you are replacing your Catalytic Converter. Otherwise, connect the harness connectors. Apply anti-seize compound to the HO2S threads before installing the sensor when replacement occurs. Check for exhaust leaks after reinstalling the oil pan skid plate if your vehicle has it and then lower the vehicle.

To replace the Catalytic Converter, first, begin with raising and supporting the vehicle. First, if present, remove the oil pan skid plate with the next step being to remove the transmission crossmember. If replacing three ways Catalytic Converter, remove heated oxygen (HO2S) sensors; otherwise, disconnect their harness connectors. Then, detach the nuts that connect the Catalytic Converter pipe (to the Exhaust Manifold and the Catalytic Converter to the Muffler) then pull out the Catalytic Converter pipe assembly from the vehicle, dispose the exhaust seals (2 and 3). For the installation, install new Exhaust Manifold seals (2 and 3) and attach the Catalytic Converter pipe to the exhaust manifolds. Fix the Catalytic Converter pipe on to the Exhaust Manifold nuts and firm them fully to 50 nm (37 lb. Ft.), then the Muffler with the Catalytic Converter nuts and tightening the clamp bolt fully to 45 nm (33 lb. Ft.). Reinstall the transmission crossmember. If the sensor is re-installed, then a special anti-seize compound, that is composed of the liquid graphite and glass beads, should be applied on the ho2s threads. If changing the three-way Catalytic Converter put on the heated oxygen (HO2S) sensors. Otherwise, connect the harness connectors. Lastly, install the oil pan skid plate if so equipped, lower the vehicle and check for exhaust leaks.