For 1990-2009 cars

### Removal Procedure

Caution: Refer to Battery Disconnect Caution in the Preface section.

1. Disconnect the negative battery cable.

Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section.

2. Disconnect the front heated oxygen sensor (HO2S1) connector.

Notice: Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

3. Carefully remove the HO2S1 from the exhaust manifold using EN-46577 Oxygen Sensor Remover/Installer.

### Installation Procedure

Important: A special anti-seize compound is used on the oxygen sensor threads. This compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from any engine and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation.

1. Coat the threads of the HO2S1 will an anti-seize compound, if needed.

Notice: Refer to Fastener Notice in the Preface section.

2. Install the HO2S1 to the exhaust manifold using EN-46577 Oxygen Sensor Remover/Installer.

Tighten
Tighten the oxygen sensor to 42 N·m (31 lb ft).

3. Connect the HO2S1 connector.
4. Connect the negative battery cable.