Removal & Installation

To Remove:

1. Disconnect or remove the following
   • Ground cable from battery

     Front O2 Sensor Connector

   • Front oxygen (a/f) sensor connector

     Engine Harness

   • Engine harness fixed by clip (a)
   • Front right side wheel

     Service Hole Cover

   • Service hole cover

     Front O2 Sensor

   • Front oxygen (A/F) sensor

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

CAUTION
If sensor is frozen, apply SUBARU CRC or its equivalent to the threaded portion of front oxygen (A/F) sensor, and leave it for one minute or more. SUBARU CRC (Part No. 004301003)

To Install:

NOTE: Before installing front oxygen (A/F) sensor, apply anti-seize compound only to the threaded portion of front oxygen (A/F) sensor to make the next removal easier.

CAUTION
Never apply anti-seize compound to protector of front oxygen (A/F) sensor.

1. Install or connect the following

   Front O2 Sensor

   • Front oxygen (A/F) sensor

     Service Hole Cover

   • Service hole cover
   • Front right side wheel

     Engine Harness

   • Engine harness using clips (A)

     Front O2 Sensor Connector

   • Front oxygen (A/F) sensor connector
   • Battery ground cable to battery

Downstream Oxygen Sensor

To Remove:

1. Disconnect or remove the following
   • Battery ground cable

     Rear O2 Sensor Connector

   • Rear oxygen sensor connector

     NOTE: If frozen, apply SUBARU CRC or its equivalent to threaded portion of rear oxygen sensor, and leave it for one minute or more. SUBARU CRC (Part No. 004301003)

     Rear O2 Sensor

   • Rear oxygen sensor

CAUTION
When removing the oxygen sensor, wait until exhaust pipe cools.

To Install:

NOTE: Before installing rear oxygen sensor, apply anti-seize compound only to threaded portion of rear oxygen sensor to make the next removal easier.

CAUTION
Never apply anti-seize compound to protector of rear oxygen sensor.

1. Install or connect the following

   Rear O2 Sensor

   • Rear oxygen sensor
   • Torque specification: 21 N.m (15.2 ft-lb)

     Rear O2 Sensor Connector

   • Rear oxygen sensor connector
   • Battery ground cable