P1130moderate severityPowertrain
Front Oxygen Sensor Circuit Malfunction Open
on 2020 Subaru Legacy 2.5L H4 · AWD
What this code means
The PCM has detected an open circuit condition in the front (upstream) oxygen sensor circuit. The sensor signal wire or heater circuit has a break, preventing the sensor from providing fuel control data to the PCM.
Symptoms
- Check Engine Light
- Engine runs in open loop
- Poor fuel economy
- Higher emissions
- Rough idle
Common causes
- O2 sensor wiring open due to heat damage or corrosion
- Disconnected O2 sensor connector
- Faulty O2 sensor with open internal element
- Corroded connector pins
- Broken wire at sensor pigtail
Diagnostic steps
- Check O2 sensor signal on scan tool (fixed voltage or no reading indicates open)
- Inspect O2 sensor connector for disconnection or corrosion
- Test O2 sensor signal wire continuity
- Check heater circuit resistance
- Inspect wiring for heat damage near exhaust
Repair notes
Repair the open wiring or replace the front O2 sensor.
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Other Powertrain codes on this vehicle
P0001
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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