P0157: Downstream O2 sensor low voltage (Bank 2 Sensor 2)
You can keep driving. Get it checked when convenient.
Can I drive with P0157?
Yes, you can keep driving. Rear sensor low voltage; emissions monitor only, drivability is unaffected.
What does P0157 mean?
P0157 stands for O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2).
Symptoms you may notice
- Check engine light on with no noticeable change in how the car drives
- Vehicle fails state emissions smog test
- Normal engine power and shifting
How much does it cost to fix?
Repair costs for code P0157 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Defective Bank 2 Sensor 2 oxygen sensor
- Exhaust leak near downstream bung
- Damaged wiring shorted to ground
- Connector water intrusion
What to do next
- Inspect underbody wiring near the Bank 2 catalytic converter.
- Look for exhaust leaks near the rear sensor bung.
- Replace Bank 2 Sensor 2.
Last updated: October 2026
Related codes
General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P0157 indicates downstream Bank 2 sensor voltage is low. Does not affect motor operation.