P0137 on Subaru WRX
Factory diagnostic protocol and troubleshooting wire for fault code P0137 specifically for the Subaru WRX (2022–2026, 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)).
1. Symptoms of P0137 on Subaru WRX
When the Engine Control Module (ECM/PCM) on your Subaru WRX (2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)) logs fault code P0137, drivers commonly observe:
2. Most Likely Causes on Subaru WRX
Historical warranty claims and technical repair bulletins for Subaru WRX point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Subaru WRX
Listen for exhaust ticking or black soot around flex pipe, flanges, and sensor bungs before the catalytic converter. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Monitor B1S2 voltage. Snap the throttle to enrich mixture; voltage should briefly spike above 0.8V. If it remains 0.0V–0.1V, sensor is defective or shorted. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Unplug harness, remove old sensor with 7/8 socket, install replacement sensor and plug firmly. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Clear DTCs and verify B1S2 holds steady between 0.45V and 0.75V during steady highway cruising. on the Subaru WRX equipped with 2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI).
Equipment for Diagnosing Subaru WRX (P0137)
Subaru WRX OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Subaru WRX.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Subaru WRX
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Subaru WRX:
4. Subaru WRX P0137 FAQs
What causes code P0137 to trigger on a Subaru WRX?
On the Subaru WRX (2.4L Turbocharged FA24F Boxer-4 (271HP WRX / 350HP STI)), P0137 is most frequently caused by Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air or Faulty downstream oxygen sensor.
Where is the OBD-II port located on my Subaru WRX?
On the Subaru WRX, the 16-pin DLC diagnostic connector is located Driver lower dash near fuse panel access door. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Subaru WRX with code P0137?
Yes. Vehicle is fully drivable, but Check Engine Light will remain illuminated. Given that P0137 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

