Three-Way Catalytic Converter Replacement (Rear-LFX)

Fig 1: Three-Way Catalytic Converter (Rear-LFX)

Courtesy of GENERAL MOTORS COMPANY

Callout	Component Name
WARNING: Refer to Exhaust Service Warning . Preliminary Procedure Remove the exhaust front pipe. Refer to Exhaust Front Pipe Replacement (AWD) Exhaust Front Pipe Replacement (FWD) .
1	Catalytic Converter - Rear Fasteners (Qty: 4) CAUTION: To prevent damage to the exhaust manifold flange or stud, make sure the flange is fully seated before tightening. CAUTION: Refer to Fastener Caution . Procedure Disconnect the oxygen sensor electrical connector. Replace fasteners and gasket with new ones. Clean and inspect the studs on the engine cylinder head, replace as necessary. Verify that the studs are fully seated. Stud collar should touch the surface of the engine cylinder head. Tighten fasteners in a criss-cross pattern. Tighten First Pass: 20 N.m (15 lb ft) Final Pass: 45 N.m (33 lb ft)
2	Gasket NOTE: Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance.
3	Catalytic Converter - Rear NOTE: If replacing catalytic converter, transfer oxygen sensor.