DTC P013A: O2 Sensor Slow Response - Rich To Lean Bank 1 Sensor 2: Notes

DTC detecting condition: 

Detected when two consecutive driving cycles with fault occur.

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Disconnect the connector from the rear oxygen sensor.
   4. Measure the resistance of harness between ECM connector and rear oxygen sensor connector.

      Connector & terminal 

      (B134) No. 33 - (B19) No. 3:

   Is the resistance less than 1 Ω?

   Yes:  Go to  2.

   No:  Repair the open circuit of harness between ECM connector and rear oxygen sensor connector.

2. CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR (SHORT TO GROUND)  .

   Measure the resistance between rear oxygen sensor connector and engine ground.

   Connector & terminal 

   (B19) No. 3 - Engine ground:

   Is the resistance 1 MΩ or more?

   Yes:  Go to  3.

   No:  Repair the short circuit to ground in harness between ECM connector and rear oxygen sensor connector.

3. CHECK REAR OXYGEN SENSOR  .

   Measure the resistance between rear oxygen sensor terminals.

   Terminals 

   No. 3 - No. 4:

   Is the resistance less than 1 Ω?

   Yes:  Replace the rear oxygen sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>REAR OXYGEN SENSOR .

   No:  Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.