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Rear Oxygen Sensor: Installation

CAUTION: If lubricant is spilt over the exhaust pipe, wipe it off with cloth to avoid emission of smoke or causing a fire.
  1. Before installing rear oxygen sensor, apply the anti-seize compound only to the threaded portion of rear oxygen sensor to make the next removal easier.
    CAUTION: Never apply anti-seize compound to the protector of rear oxygen sensor.

    Anti-seize compound: 

    NEVER-SEEZ NSN, JET LUBE SS-30 or equivalent 

  2. Install the rear oxygen sensor.

    Tightening torque: 

    21 N.m (2.1 kgf-m, 15.5 ft-lb) 

    Fig 1: Locating Rear Oxygen Sensor
    G08315457Courtesy of SUBARU OF AMERICA, INC.
  3. Connect the rear oxygen sensor connector.
    NOTE: Be careful not to allow the rear oxygen sensor harness to interfere with the sensor unit and the front oxygen (A/F) sensor harness.
    Fig 2: Connecting Rear Oxygen Sensor Connector
    G11584121Courtesy of SUBARU OF AMERICA, INC.
  4. Install the under cover. Ref. to INSTALLATION , Front Under Cover.
  5. Lower the vehicle.
  6. Connect the battery ground terminal.
Fig 3: Connecting Battery Ground Terminal
G08317298Courtesy of SUBARU OF AMERICA, INC.