Ask Andy AIP0155 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
What it means, what causes it, and what it costs to fix.
What P0155 means
The heater in the upstream oxygen sensor on bank 2 (the side without cylinder 1) isn't working, or its circuit has a fault.
Can I drive with P0155?
Severity: Low. Not urgent. Fix it when convenient.
Safe to drive.
Get a diagnosis for your exact car
Tell Andy your year, make, model, and symptoms. You'll get best case, most likely, and worst case, with parts and labor costs. Free, in about 15 seconds.
Ask Andy about P0155Symptoms
- Check engine light
- Slightly reduced fuel economy
Common causes
Most likely first.
- Burned-out O2 heater
- Blown fuse
- Damaged wiring
How to diagnose P0155
- Check the fuse.
- Test heater resistance.
- Inspect wiring near the exhaust manifold.
Tip: most US auto parts stores will read your codes for free.
Repair costs
| Bank 2 upstream O2 sensor | $150–$350 installed |
Typical US prices. Your vehicle, region, and shop rates will change these.
P0155 FAQ
What does P0155 mean?
P0155 means "O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)." The heater in the upstream oxygen sensor on bank 2 (the side without cylinder 1) isn't working, or its circuit has a fault.
Can I drive with a P0155 code?
Safe to drive.
What is the most common cause of P0155?
The most common cause is: Burned-out O2 heater. Other causes include blown fuse and damaged wiring.
How much does it cost to fix P0155?
Typical repairs run about $150 to $350 in the US, depending on the cause. Bank 2 upstream O2 sensor: $150–$350 installed.
Still not sure what's wrong?
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