Chevrolet Silverado / GMC Sierra. Service manual — part 1818

Fig. 99: View Of HO2S
Courtesy of GENERAL MOTORS CORP.

24. Remove the HO2S (1-4) from the catalytic converter assembly.

Installation Procedure

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 as exhaust component and if for any

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Exhaust - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 100: View Of HO2S
Courtesy of GENERAL MOTORS CORP.

1. If replacing the catalytic converter assembly, perform the following steps, otherwise

proceed to step 4.

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

12377953, or equivalent.

reason the sensor is to be reinstalled, the threads must have anti-
seize compound applied before the reinstallation.

NOTE:

Refer to Component Fastener Tightening Notice .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Exhaust - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

3. Install the HO2S (1-4) to the catalytic converter assembly.

Tighten: Tighten the sensors to 42 N.m (31 lb ft).

Fig. 101: View Of Exhaust Manifold Nuts & Exhaust Seals
Courtesy of GENERAL MOTORS CORP.

4. Install the NEW exhaust seals (2 and 3) as required.

NOTE:

Refer to Fastener Notice .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Exhaust - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

5. Install the catalytic converter assembly to the muffler.

6. Install the catalytic converter assembly to the exhaust manifolds.

7. Install the catalytic converter to exhaust manifold nuts (1).

Tighten: Tighten the nuts to 50 N.m (37 lb ft).

Fig. 102: View Of Catalytic Converter To Muffler Nuts
Courtesy of GENERAL MOTORS CORP.

8. Install the catalytic converter to muffler nuts.

Tighten: Tighten the nuts to 45 N.m (33 lb ft).

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Exhaust - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado