P0137 Ford F-150
O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) · Powertrain Code · Medium · Repair: Moderate
What is P0137?
Low voltage from the downstream O2 sensor on bank 1.
When the Ford F-150 triggers code P0137 (o2 sensor circuit low voltage (bank 1, sensor 2)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Ford F-150.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Ford F-150.
Common Causes on Ford F-150
- Failed downstream O2 sensor (bank 1 sensor 2)
- Exhaust leak between catalytic converter and downstream sensor
- Wiring or connector damage from road debris (sensor is under the vehicle)
- Contaminated sensor from coolant or oil entering the exhaust
Symptoms
- Check engine light
- Poor fuel economy
- Slight sulfur smell from exhaust
- Failed emissions test
Notes for Ford F-150
If both P0137 and P0430 are present, the catalytic converter may be failing — diagnose the converter before replacing just the O2 sensor.