P0135 on a Honda: Causes, Fixes & Repair Cost
🟠 Moderate severity · drivable
Safe to drive, but the sensor warms up slowly and fuel economy and emissions may suffer until the heater circuit is fixed.
What P0135 means on a Honda
On a Honda, P0135 means the heater inside the bank 1 upstream oxygen sensor isn't working. That sensor measures the exhaust right before the catalytic converter and uses its heater to reach working temperature fast after a cold start. A dead heater circuit makes the sensor read slowly and can throw off the fuel mixture.
Is P0135 common on Hondas?
P0135 is common on Hondas with higher mileage, especially the Civic, Accord, and CR-V, where upstream oxygen sensors wear out over time. The heater element is what fails most often. Replacing the sensor is the standard fix and a common DIY job on these cars.
Commonly reported on: Civic, Accord, CR-V, Pilot.
Symptoms
- Check engine light is on
- Slower sensor warm-up after cold start
- Slightly worse fuel economy
- Possible failed emissions test
Common causes
- most common: Failed O2 sensor heater element
- common: Blown heater circuit fuse or relay
- common: Damaged or corroded wiring or connector at the sensor
- less common: Defective aftermarket sensor
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the upstream oxygen sensor | Yes | $80–200 |
| Replace the blown fuse or relay | Yes | $10–40 |
| Repair the wiring or connector | Mechanic | $80–200 |
Frequently asked questions
Other common Honda codes
P0135 on other brands
Looking for the full (non-brand-specific) guide? See the P0135 code page →
Browse all Honda codes: Honda hub →
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.