DTC P0130: A/F/O2 Sensor Circuit Bank 1 Sensor 1: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Clear Memory Mode>OPERATION , and inspection mode Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Inspection Mode>PROCEDURE .

Use the check board when measuring the ECM terminal voltage and resistance.

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>Engine Electrical System>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CHECK FRONT OXYGEN (A/F) SENSOR DATA .
1. Start the engine and warm up engine until coolant temperature is higher than 75°C (167°F).
2. Idle the engine for one minute or more.
3. Read the value of «A/F Sensor #11» using the Subaru Select Monitor or a general scan tool.
  NOTE:
  - Subaru Select Monitor
    For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>Subaru Select Monitor .
  - General scan tool
    For detailed operation procedures, refer to the general scan tool operation manual.
Is the value of «A/F Sensor #11» 1.20 - 3.00 V?

Yes: Go to 2

No: Go to 3
CHECK FRONT OXYGEN (A/F) SENSOR DATA .
1. Race the engine so that the engine speed reaches 3, 000 rpm. (Five times in total)
2. Read the value of «A/F Sensor #11» at racing using the Subaru Select Monitor or a general scan tool.
  NOTE:
  - To increase engine speed to 3, 000 rpm, slowly depress accelerator pedal for approximately 5 seconds, and quickly release accelerator pedal to decrease engine speed.
  - Normally, the air fuel ratio is rich during racing.
Is the value of «A/F Sensor #11» 2.5 V or more?

Yes: Go to 5

No: Go to 3
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from front oxygen (A/F) sensor.
4. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector.
  Connector & terminal
  
  (E158) No. 15 - (E24) No. 1:
  
  (E158) No. 27 - (E24) No. 4:
  
  (E158) No. 39 - (E24) No. 5:
Is the resistance less than 1 Ω?

Yes: Go to 4

No: Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 15 - Engine ground:

(E158) No. 27 - Engine ground:

(E158) No. 39 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 5

No: Repair the short circuit to ground in harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK EXHAUST SYSTEM .
Check exhaust system parts.
NOTE:
Check the following items.
- Looseness and improper fitting of exhaust system parts
- Damage (crack, hole etc.) of parts
- Looseness of front oxygen (A/F) sensor
- Loose part and improper installation between front oxygen (A/F) sensor and rear oxygen sensor
Is there any fault in exhaust system?

Yes: Repair or replace faulty parts.

No: Replace the front oxygen (A/F) sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>Front Oxygen (A/F) Sensor .