Installation Procedure

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Fig 1: Identifying Catalytic Converter Outlet Pipe

Courtesy of GENERAL MOTORS CORP.

Install the catalytic converter (1) in reverse order of removal by starting with the catalytic converter outlet pipe angled toward the left side of the vehicle and positioning the right side catalytic converter pipe above the frame. Rotate the catalytic converter outlet pipe toward the rear of the vehicle and lift the left side catalytic converter pipe up above the frame. Then position the catalytic converter (1) to the exhaust manifolds.

Fig 2: Locating Exhaust Hangers

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Install the exhaust hanger insulators to the exhaust system.

NOTE: Refer to Fastener Notice in Cautions and Notices.

Fig 3: Exhaust Pipe To Muffler Joint

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Install the exhaust muffler nuts. Ensure the catalytic converter is held in the installed position before tightening the nuts.
Tighten: Tighten the nuts to 45 N.m (33 lb ft).

Fig 4: View Of Right Catalytic Converter To The Exhaust Manifold Connection

Courtesy of GENERAL MOTORS CORP.

Install the right exhaust manifold pipe nuts. Ensure the catalytic converter is held in the installed position before tightening the nuts.
Tighten: Tighten the nuts to 50 N.m (37 lb ft).

Fig 5: View Of Left Catalytic Converter To The Exhaust Manifold Connection

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Install the left exhaust manifold pipe nuts.
Tighten: Tighten the nuts to 50 N.m (37 lb ft).
Install the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.
Remove the transmission jack.
If equipped with 4WD, install the front propeller shaft. Refer to Propeller Shaft Replacement - Front in Propeller Shaft.
Install the rear propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft.

IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

If reinstalling the old sensors, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.

Fig 6: Removing/Installing HO2S From Catalytic Converter

Courtesy of GENERAL MOTORS CORP.

NOTE: Refer to Component Fastener Tightening Notice in Cautions and Notices.

IMPORTANT: If the HO2S sensor is connected to the main wiring harness during installation. Rotate the HO2S sensor several turns counterclockwise before threading the HO2S sensor into the catalytic converter. This action of initially reverse winding of the pigtail wires will prevent a condition where the HO2S sensor pigtail wires become severely twisted or binding once the HO2S sensor is installed into the catalytic converter.

Install both front HO2S sensors (1) to the catalytic converter.
Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Install both rear HO2S (2) to the catalytic converter.
Tighten: Tighten the sensor to 42 N.m (31 lb ft).
Lower the vehicle.