Fixing P0135 in Your 2022 Subaru Impreza
Your 2022 Subaru Impreza displayed P0135—O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1. The upstream oxygen sensor's heater on the driver's side has failed.
Without the heater, your Impreza runs inefficiently until natural engine heat warms the sensor—wasting fuel.
Symptoms
- Check engine light on
- 10-18% reduced fuel economy
- Rough cold-start idle
- Hesitation during acceleration
- Extended warm-up period
- Failed emissions test
Root Causes
Heater Element Failure (64% Likelihood)
Your 2022 Impreza's 2.0L boxer engine creates thermal stress. By 40,000-70,000 miles, heater failures become common.
Wiring Damage (22% Likelihood)
Boxer engine wiring near exhaust suffers heat damage.
Blown Fuse (9% Likelihood)
Check fuse first—easiest fix.
ECM Issue (5% Likelihood)
Rare ECM faults trigger false codes.
Diagnosis
- Verify P0135
- Check fuse
- Inspect wiring
- Test heater resistance (4-12 ohms)
- Check voltage
- Monitor live data
Repair Costs
Dealership
If within warranty, free.
Out of warranty: $248-$370
Independent Shop
Cost: $168-$300
DIY
Cost: $68-$132
Time: 38-55 minutes
Parts
- OEM Subaru: $110-$152
- Denso: $68-$112
- Bosch: $75-$122
Prevention
- Use Top Tier fuel
- Address oil consumption
- Fix exhaust leaks
- Avoid unapproved additives
- Take longer drives
Driving with P0135
Safe short-term, but fuel economy drops 10-18%. Schedule repairs within 2 weeks to prevent catalytic converter damage ($950-$2,250).
When to Get Help
- Under warranty
- Uncomfortable with boxer engine work
- Code returns after replacement
- Multiple codes
2022 Impreza Notes
The Impreza's boxer engine places sensors uniquely. Some owners report failures around 50,000 miles—check dealer for TSBs.