Impreza WRX STI F4-2.5L Turbo (2008)
Oxygen Sensor: Service and Repair
Front Oxygen (A/F) Sensor
Front Oxygen (A/F) Sensor
REMOVAL
1. Set the vehicle on a lift.
2. Disconnect the ground cable from the battery.
3. Disconnect the connector from the front oxygen (A/F) sensor, and remove the clip (A) holding the return hose and front oxygen (A/F) sensor
harness.
4. Remove the clips (A) holding the front oxygen (A/F) sensor harness to the engine harness stay.
5. Lift up the vehicle
6. Remove the under cover.
7. Apply spray-type lubricant or equivalent to the threaded portion of front oxygen (A/F) sensor, and leave it for one minute or more.
8. Remove the front oxygen (A/F) sensor.
CAUTION: When removing the oxygen (A/F) sensor, wait until exhaust pipe cools, otherwise it will damage the exhaust pipe.