Begin by raising the 1500 series vehicle through proper support before the Catalytic Converter replacement process can begin. Start work by removing the bolts from the oil pan skid plate and skid plate (if present) then disconnect the transmission crossmember. First disconnect the right front heated
Oxygen Sensor (HO2S) electrical connector then remove the right front connector position assurance (CPA) retainer. Unplug the electrical connector of right rear ho2s before removing its cpa retainer. Repeat this process on the left rear ho2s. Vehicles with 4l60-e/4l70-e automatic transmissions need the left front ho2s electrical connector removed and its corresponding cpa retainer detached. Vehicles which have regular production options (RPOs) lc9/lmg/ly5/l76/ly2 require removal of
Muffler to Catalytic Converter nuts. Rpo l92 calls for Muffler to Catalytic Converter nuts to be taken out. Lift out the ho2s and Catalytic Converter to
Exhaust Manifold nuts before pulling the Catalytic Converter assembly free from exhaust manifolds and exhaust Muffler. When needing to replace the Catalytic Converter assembly you must remove both exhaust seals and the ho2s from the assembly. The installation includes application of gm p/n 12377953 anti-seize compound to ho2s threads before mounting to the Catalytic Converter assembly and torqueing at 42 n.m (31 lb ft). After installing new exhaust seals on the manifolds and Muffler, fasten the Catalytic Converter assembly to its positions while tightening nuts to 50 n.m (37 lb ft). When installing the ho2s on vehicles with rpo l92 begin by tightening the Catalytic Converter to Muffler nuts to 45 n.m (33 lb ft). Rpos lc9/lmg/ly5/l76/ly2 require installation of Catalytic Converter to Muffler nuts with a torque of 45 n.m (33 lb ft). The installation process includes reconnecting electrical connectors for the ho2s followed by retainer installation. After finishing, position the oil pan skid plate then fasten the bolts to 28 n.m (21 lb ft) and carefully lower the vehicle.