Front Oxygen (A/F) Sensor: Removal

Set the vehicle on a lift.
Remove the collector cover.
Disconnect the ground cable from battery.

Fig 1: Disconnecting Ground Cable From Battery
Courtesy of SUBARU OF AMERICA, INC.
Remove the air intake duct and air cleaner case. Refer to REMOVAL , Air Intake Duct. Refer to REMOVAL , Air Cleaner Case.
Disconnect the connector from front oxygen (A/F) sensor.

Fig 2: Identifying Connector From Front Oxygen (A/F) Sensor
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle.
Remove the under cover.
Apply spray-type lubricant or equivalent 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
Courtesy of SUBARU OF AMERICA, INC.