Installation Procedure

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

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

Fig 1: View Of HO2S

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If replacing the catalytic converter assembly, perform the following steps, otherwise proceed to step 4.
If reinstalling the old sensors, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.

NOTE: Refer to Component Fastener Tightening Notice .

NOTE: Refer to Fastener Notice .

Install the HO2S (1-4) to the catalytic converter assembly.
Tighten: Tighten the sensors to 42 N.m (31 lb ft).

Fig 2: View Of Exhaust Manifold Nuts & Exhaust Seals

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Install the NEW exhaust seals (2 and 3) as required.
Install the catalytic converter assembly to the muffler.
Install the catalytic converter assembly to the exhaust manifolds.
Install the catalytic converter to exhaust manifold nuts (1).
Tighten: Tighten the nuts to 50 N.m (37 lb ft).

Fig 3: View Of Catalytic Converter To Muffler Nuts

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Install the catalytic converter to muffler nuts.
Tighten: Tighten the nuts to 45 N.m (33 lb ft).

Fig 4: View Of Various Connectors & Clips

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For vehicles equipped with 4WD perform the following steps, for vehicles equipped with 2WD proceed to step 13.
Connect the engine wiring harness electrical connector (6) to the left front HO2S electrical connector (7).
Install the CPA retainer.
Install the HO2S electrical connector clip to the fuel line clip (2).

Fig 5: View Of Various Connectors & Clips

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For vehicles equipped with 4WD perform the following steps, connect the engine wiring harness electrical connector (7) to the left front HO2S electrical connector (8).
Install the left front CPA retainer.

Fig 6: View Of Engine Wiring Harness Electrical Connector & HO2S Electrical Connector

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Connect the engine wiring harness electrical connector (1) to the left rear HO2S electrical connector (2).
Install the left rear HO2S electrical connector clip to the frame.
Install the CPA retainer.

Fig 7: View Of Engine Harness Clip & Electrical Connectors

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Connect the engine wiring harness electrical connector (2) to the right rear HO2S electrical connector (1).
Install the right rear CPA retainer.
Install the right rear HO2S electrical connector clip to the engine harness clip (3).
Connect the right front HO2S electrical connector (5) to the engine wiring harness electrical connector (4).
Install the right front CPA retainer.

Fig 8: View Of Oil Pan Skid Plate & Bolts

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Install the transmission crossmember. Refer to Transmission Support Crossmember Replacement (2WD 1500/2500) or Transmission Support Crossmember Replacement (2WD 2500 HD/3500) or Transmission Support Crossmember Replacement (4WD 1500/2500) or Transmission Support Crossmember Replacement (4WD 2500 HD/3500) .
Position the oil pan skid plate and install the oil pan skid plate bolts, if equipped.
Tighten: Tighten the bolts to 28 N.m (21 lb ft).
Lower the vehicle.