P0156moderate severityPowertrain
O2 Sensor Circuit Bank 2 Sensor 2
on 2004 Subaru Legacy 3.0L H6 · AWD
What this code means
General malfunction in the downstream O2 sensor on Bank 2.
Symptoms
- Check Engine Light
- Failed emissions
Common causes
- Faulty sensor
- Wiring issue
- Exhaust leak
Diagnostic steps
- Test sensor voltage
- Inspect wiring
- Check for leaks
Repair notes
Replace sensor.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
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P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1