P0159: Downstream O2 sensor slow response (Bank 2 Sensor 2)
You can keep driving. Get it checked when convenient.
Can I drive with P0159?
Yes, you can keep driving. Rear O2 sensor reacts slowly; usually safe to drive for a short time, but get it checked.
What does P0159 mean?
P0159 stands for O2 Sensor Circuit Slow Response (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 P0159 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:
- Aging Bank 2 rear oxygen sensor
- Minor exhaust leak near rear sensor
- Soot contamination on sensor tip
- Failing catalytic converter
What to do next
- Check for exhaust leaks at the rear converter flange.
- Replace Bank 2 Sensor 2.
- Clear code.
Last updated: October 2026
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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 P0159 indicates a sluggish downstream sensor on Bank 2. Safe to keep driving.