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 1288 (ENGINE EXHAUST SYSTEM)REPAIR INSTRUCTIONSCATALYTIC CONVERTER REPLACEMENT (2WD)INSTALLATION 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 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to FASTENER NOTICE .

Install the TWC to the vehicle.
Install the hangers to the TWC (2).
Install the bolts securing the Three-Way Catalytic Converter (TWC) to the muffler/tail pipe assembly.
1. Tighten
2. Tighten the TWC to muffler/tail pipe assembly bolt to 32 N.m (24 lb ft).
Install the bolts securing the front pipe to the Three-Way Catalytic Converter (TWC).
1. Tighten
2. Tighten the TWC to front pipe bolts to 43 N.m (32 lb ft).
Install the Heated Oxygen Sensor 2 (HO2S2). Refer to HEATED OXYGEN SENSOR 2 or HEATED OXYGEN SENSOR 2 in Engine Controls - 1.8L (LV6) or HEATED OXYGEN SENSOR 2 in Engine Controls - 1.8L (LNK).
Install the Heated Oxygen Sensor 1 (HO2S1). Refer to HEATED OXYGEN SENSOR 1 or HEATED OXYGEN SENSOR 1 in Engine Controls - 1.8L (LV6) or HEATED OXYGEN SENSOR 1 in Engine Controls - 1.8L (LNK).
Lower the vehicle.

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.