P0135Medium urgency
O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
Emission · Oxygen Sensors
⚠️ Safe to drive short-term — will affect fuel economy.
What this means
The upstream oxygen sensor heater on Bank 1 is not functioning. The heater brings the sensor to operating temperature quickly after cold start.
Likely causes
- Failed O2 sensor heater elementMost common
- Wiring harness damageCommon
- ECM faultLess common
Estimated repair cost
O2 sensor replacement$150 – $350
Wiring repair$75 – $200
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Frequently asked questions
What does P0135 mean?
The upstream oxygen sensor heater on Bank 1 is not functioning. The heater brings the sensor to operating temperature quickly after cold start.
Is P0135 serious?
Safe to drive short-term — will affect fuel economy.
How much does it cost to fix P0135?
Repair costs for P0135 range from $150 – $350 depending on the root cause and your vehicle.
Can I drive with P0135?
You can drive short distances but should have it repaired within 1-2 weeks to prevent further damage.