P0151moderate severityPowertrain
O2 Sensor Circuit Low Voltage Bank 2 Sensor 1
on 1998 Subaru Impreza 2.5L H4 · AWD
What this code means
The upstream O2 sensor voltage on Bank 2 is staying low.
Symptoms
- Check Engine Light
- Lean running Bank 2
- Rough idle
Common causes
- Vacuum leak Bank 2
- Faulty sensor
- Exhaust leak
- Low fuel pressure
Diagnostic steps
- Check vacuum leaks Bank 2
- Monitor sensor voltage
- Test fuel pressure
Repair notes
Fix leak or replace sensor.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
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