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2014 SUBARU LEGACY

3.6L H6AWDCVTgas
10 active safety recalls on this vehicle — view recalls
Repairs0Labor504Torque4989Fluid9DTC903Battery0Maintenance0Recalls10
P1130moderate severityPowertrain

Front Oxygen Sensor Circuit Malfunction Open

on 2014 Subaru Legacy 3.6L H6 · 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

  1. Check O2 sensor signal on scan tool (fixed voltage or no reading indicates open)
  2. Inspect O2 sensor connector for disconnection or corrosion
  3. Test O2 sensor signal wire continuity
  4. Check heater circuit resistance
  5. Inspect wiring for heat damage near exhaust

Repair notes

Repair the open wiring or replace the front O2 sensor.

Other Powertrain codes on this vehicle

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