Front Oxygen (A/F) Sensor: Removal

Disconnect the ground cable from battery.

Fig 1: Disconnecting Ground Cable From Battery
Courtesy of SUBARU OF AMERICA, INC.
Remove the air intake duct. Refer to AIR INTAKE DUCT .
Disconnect the front oxygen (A/F) sensor connector, and remove the clip holding the front oxygen (A/F) sensor harness.

Fig 2: Identifying Front Oxygen (A/F) Sensor Connector, Rear Oxygen Sensor Connector And Harness Clip
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle.
Remove the under cover. Refer to FRONT UNDER COVER .
Apply spray-type lubricant to the threaded portion of front oxygen (A/F) sensor, and leave it for one minute or more.
Remove the front oxygen (A/F) sensor.

CAUTION: When removing the front oxygen (A/F) sensor, wait until exhaust pipe cools, otherwise it will damage the exhaust pipe.

Fig 3: Identifying Front Oxygen (A/F) Sensor And Rear Oxygen Sensor

Courtesy of SUBARU OF AMERICA, INC.