What P0135 Means for Your 2019 Sentra
Your 2019 Nissan Sentra has logged a P0135 diagnostic code, indicating a malfunction in the oxygen sensor heater circuit for Bank 1, Sensor 1. The 2019 Sentra came with either the 1.8L four-cylinder (124 hp) or the turbocharged 1.6L (188 hp in SR Turbo models). Both are inline engines with a single exhaust bank.
At 5-6 years old, your Sentra may be experiencing normal O2 sensor wear.
Symptoms
- Check engine light on
- Reduced fuel economy
- Rough cold idle
- Extended warm-up
- Emissions test failure
Common Causes
Worn Heater Element
Normal wear at this age and mileage.
Connector Corrosion
Years of heat and road exposure cause corrosion.
Wiring Damage
Heat degrades wiring insulation over time.
Blown Fuse
Check the O2 heater fuse first.
Warranty Status
- Bumper-to-Bumper: Expired
- Powertrain: Expired
- Federal Emissions: 8 years/80,000 miles (may still apply)
Repair Costs
- Dealer: $160-$300
- Independent shop: $130-$250
- DIY: $40-$100 for sensor
DIY Replacement
The upstream O2 sensor on the Sentra is accessible:
- Work with cold engine
- Apply penetrating oil
- Disconnect connector
- Use O2 sensor socket
- Apply anti-seize to new sensor
- Torque to spec, clear codes