Understanding P0135 on Your 2020 Maxima
Your 2020 Nissan Maxima has triggered a P0135 diagnostic code, indicating a malfunction in the oxygen sensor heater circuit for Bank 1, Sensor 1. The 2020 Maxima is powered by a 3.5L V6 engine (300 hp). On this transverse-mounted V6, Bank 1 is typically the rear cylinder bank (toward the firewall).
At 4-5 years old, your Maxima may be experiencing early O2 sensor wear.
Symptoms
- Check engine light on
- Reduced fuel economy
- Rough cold idle
- Extended warm-up
- Emissions test failure
Common Causes
O2 Sensor Heater Element Wear
The heater element degrades from thermal cycling.
Connector Corrosion
Heat and road exposure cause corrosion over time.
Wiring Damage
Heat from the V6 exhaust can damage wiring.
Blown Fuse
Check the O2 heater fuse first.
Warranty Status
- Bumper-to-Bumper: Likely expired
- Powertrain: 5yr/60k (may apply)
- Federal Emissions: 8yr/80k
Repair Costs
- Dealer: $200-$350
- Independent shop: $160-$300
- DIY: $60-$130
DIY Considerations
The V6's transverse mounting makes Bank 1 Sensor 1 access challenging. May require working from below or removing engine covers.