Check Engine Code
P0137
O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
What P0137 means
Downstream sensor signal is persistently below the normal switching range. A 'lean' downstream reading often means an exhaust leak between the cat and sensor, or a failed sensor.
Symptoms
- CEL
- Often paired with P0420 if catalyst-related
- Rarely affects drivability
Likely causes (most common first)
- Exhaust leak after the catalytic converter
- Failed downstream O2 sensor
- Wiring fault
- Severely degraded catalyst (no oxygen storage)
Can I keep driving?
Low — mostly emissions/economy
Typical repair cost
DIY fixes can start near $40 (parts only). Shop repairs for P0137 typically run up to $500 depending on the underlying cause and vehicle. Start with the most common cause — Exhaust leak after the catalytic converter — before throwing parts at it.
Recommended parts & tools for P0137
Most common fix for P0137:
Oxygen (O2) sensorCompare the parts and tools that pair with AXLY:
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