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.

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. Disconnect the Heated Oxygen Sensor (HO2S1) electrical connector.
3. Remove the following components from the exhaust pipe:

• | 2 oxygen sensor nuts

• | The oxygen sensor gasket

• | The oxygen sensor (2)

4. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
5. Remove the following components from the exhaust manifold flange:

• | 2 bolts

• | The springs

6. Remove the exhaust gasket.
7. Remove 1 bolt (1) from the manifold support bracket to exhaust manifold.
8. Lower the vehicle.
9. Remove the 6 upper heat insulator bolts.
10. Remove the heat insulator.
11. Remove the 5 exhaust manifold nuts (1).
12. Remove the following components:

• | The exhaust manifold

• | The gasket

13. Remove the 3 lower heat insulator bolts.
14. Remove the lower heat insulator.

### Installation Procedure

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.

1. Install the lower heat insulator to the exhaust manifold. Secure the insulator using 3 bolts.

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

2. Install the following components:

• | The new exhaust manifold gasket

• | The exhaust manifold

3. Secure the manifold using 5 exhaust manifold nuts (1).

Tighten
Tighten the exhaust manifold nuts to 48 N·m (36 lb ft).

4. Install the upper heat insulator. Secure the insulator using 6 bolts.

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

5. Raise and properly support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
6. Install 1 bolt (1) to the exhaust manifold support bracket.

Tighten
Tighten the exhaust manifold bracket bolt to 32 N·m (24 lb ft).

7. Install the front exhaust pipe to the manifold flange.

Use the following components in order to secure the front exhaust pipe.

• | 2 bolts

• | 2 springs

Tighten
Tighten the front exhaust pipe bolts to 62 N·m (46 lb ft).

8. Install the following components to the front exhaust pipe:

• | The new oxygen sensor gasket

• | The oxygen sensor

9. Secure the heated oxygen sensor using 2 nuts.

Tighten
Tighten the heated oxygen sensor nuts to 41 N·m (30 lb ft).

10. Connect the (HO2S1) electrical connector.
11. Connect the negative battery cable.

Tighten
Tighten the battery cable bolt to 15 N·m (11 lb ft).