For 1990-2009 cars

### Removal Procedure

Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Important: If only replacing the Warm Up Catalytic Converter (WU/TWC), it is not necessary to remove the exhaust manifold.

Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

1. Disconnect the negative battery cable.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Remove the two bolts and the front pipe/three way catalytic converter (TWC) assembly (4) from the exhaust manifold, or the Warm Up Catalytic Converter (WU/TWC) (3) if equipped.
4. Lower the vehicle.
5. Disconnect the Heated Oxygen Sensor (HO2S 1) electrical connector (1).
6. Remove the Heated Oxygen Sensor (HO2S 1).
7. Remove the three bolts and the exhaust manifold heat shield from the exhaust manifold.
8. Remove the following from the exhaust manifold:

• | The four bolts

• | The three nuts

• | The engine hanger

9. Remove the exhaust manifold (2).
10. Remove the exhaust manifold gasket from the cylinder head.

### Installation Procedure

1. Install the new exhaust manifold gasket (2) to the cylinder head.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the exhaust manifold (1). Secure the manifold with the engine hanger, four bolts and three nuts.

Tighten
Tighten the exhaust manifold bolts and nuts to 23 N·m (17 lb ft).

3. Install the exhaust manifold heat shield to the exhaust manifold (1). Secure the exhaust manifold heat shield with the three bolts.

Tighten
Tighten the heat shield bolts to 15 N·m (11 lb ft).

4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
5. Install the front pipe/TWC (4), or the Warm Up/TWC assembly (3) to the exhaust manifold with a new seal. Secure the assembly with the two bolts.

Tighten
Tighten the exhaust manifold-to-front pipe/TWC assembly bolts to 45 N·m (33 lb ft).

6. Lower the vehicle.
7. Install the Heated Oxygen Sensor (HO2S 1).

Tighten
Tighten the Heated Oxygen Sensor (HO2S 1) to 40 to 50 N·m (29 to 36 lb ft).

8. Connect the HO2S 1 electrical connector (1).
9. Connect the negative battery cable.
10. Check the exhaust system for exhaust gas leakage.