Subaru Fault Code
Free · no signupP0137
Check Engine Light Solid / Normal Drive
System
Exhaust / O2
Symptom
Check Engine Light Solid / Normal Drive
Diagnosis & fix steps
LOGIC: O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2).
ACTION: Inspect the downstream oxygen sensor harness near the rear catalytic converter. Check for wire abrasion against heat shields; backprobe signal line (must rise above 0.6V on snap throttle).
Red Seal field insights
Harness Snagging: The rear oxygen sensor harness hangs near the transmission tunnel/driveshaft shield; road debris or ice buildup snags the wiring, grounding out the signal wire.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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