Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

SYS.OK|MANUAL.DB● LIVE

HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1732 (ENGINE EXHAUST SYSTEM)REPAIR INSTRUCTIONSEXHAUST SEAL REPLACEMENTINSTALLATION PROCEDURE

2003 Chevrolet TrailBlazer 4.2 S, 4WD

Installation Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Installation Procedure

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Install the exhaust manifold pipe seal(s).
Raise the catalytic converter or exhaust manifold pipe using the adjustable jackstands.
NOTE: Refer to FASTENER NOTICE in Cautions and Notices.
If equipped with a 6.0L or 8.1L engine, perform the following:
1. Install the exhaust hanger mounting bracket bolts.
2. Install the left exhaust manifold pipe nuts.
Tighten
- Tighten the bolts to 12 N.m (106 lb in).
- Tighten the nuts to 50 N.m (39 lb ft).
Fig 1: Installing Left Exhaust Manifold Pipe, Seals & Nuts (6.0L & 8.1L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 6.0L or 8.1L engine, install the right exhaust manifold pipe nuts.
Tighten

Tighten the nuts to 50 N.m (39 lb ft).

Fig 2: Installing Right Exhaust Manifold Pipe Nuts (6.0L & 8.1L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 4.3L, 4.8L, or 5.3L engine, install the right exhaust manifold pipe nuts.

Fig 3: Installing Right Exhaust Manifold Pipe Nuts (4.3L, 4.8L & 5.3L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 4.3L, 4.8L, or 5.3L engine, install the left exhaust manifold pipe nuts.
Tighten

Tighten the nuts to 50 N.m (39 lb ft).

Fig 4: Installing Left Exhaust Manifold Pipe Nuts (4.3L, 4.8L & 5.3L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 6.0L or 8.1L engine, perform the following:
1. Connect the oxygen sensor electrical connector (1).
2. Connect the CPA retainer.
Remove the adjustable jackstands from catalytic converter or exhaust manifold pipe.

Fig 5: Connecting Oxygen Sensor Electrical Connector & CPA Retainer (6.0L & 8.1L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
1. Connect the oxygen sensor electrical connector (1).
2. Connect the CPA retainer.
3. Clip the oxygen sensor electrical connector to the hose clip.
Fig 6: Connecting Oxygen Sensor Electrical Connector, CPA Retainer & Clip (4.3L, 4.8L & 5.3L)
Courtesy of GENERAL MOTORS CORP.
If equipped with a 4.3L, 4.8L, or 5.3L engine, perform the following:
1. Connect the forward oxygen sensor electrical connector.
2. Connect the CPA retainer.
3. Install the clip around the engine harness and the oxygen sensor pigtail.
Lower the vehicle.

Fig 7: Connecting Forward Oxygen Sensor Electrical Connector, CPA Retainer & Clip (4.3L, 4.8L & 5.3L)
Courtesy of GENERAL MOTORS CORP.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.