For 1990-2009 cars

### Removal Procedure

Caution: The heated oxygen sensors each use a permanently attached pigtail and connector. Do not remove the pigtail from the heated oxygen sensor. Damage or removal of the pigtail or the connector affects proper operation of the heated oxygen sensor. Handle the oxygen sensor carefully. Do not drop the oxygen sensor. Keep the in-line connector and the louvered end free of grease, dirt, or other contaminants. Do not use cleaning solvents of any type. Do not repair the wiring, the connector, or the terminals. Replace the oxygen sensor if the pigtail wiring, the terminals, or the connector is damaged. Proper oxygen sensor operation requires an external air reference. This external air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, the connectors, or the terminals results in the obstruction of the air reference and degrades the oxygen sensor performance. A dropped oxygen sensor is a bad oxygen sensor.

Caution: The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

1. Open the hood.
2. Disconnect the battery.

• | Remove the ground connection from the ground terminal.

• | Loosen the nut.

3. Remove the oxygen sensor (1).

• | Disconnect the wiring harness connector (3).

• | Disconnect the wiring harness (2) from bracket.

### Installation Procedure

Caution: Refer to Fastener Caution in the Preface section.

1. Install the oxygen sensor 1.

Tighten
Tighten the oxygen sensor to 40 N·m (30 lb ft).

• | Connect the wiring harness into the bracket.

• | Install the wiring harness plug.

2. Connect the battery.

Install the ground connection to ground terminal.

Tighten
Tighten the nut to 5 N·m (44 lb in).

3. For programming procedures, refer to Control Module References.
4. Close the hood.