HO2S Heater Resistance Bank 1 Sensor 3
What it means
P0055 means the heater element inside the Bank 1, Sensor 3 oxygen sensor is out of its expected resistance range — the heater that brings the sensor up to temperature is failing. Sensor 3 sits downstream in the exhaust, so this is an emissions-monitoring fault rather than a running problem.
Can I keep driving? Safe to drive — this is an emissions monitoring fault; the car runs normally but will show a check-engine light and may fail an emissions test.
Real-world scan data
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Fails or is not ready for an emissions test
- Oxygen-sensor heater monitor won't complete
Common causes
Most likely first
- Failed oxygen-sensor heater element (most common — replace the sensor)Likely
- Corroded or damaged wiring/connector at the sensorCommon
- Blown fuse or bad relay feeding the heater circuitCommon
- ECM heater-driver fault (least likely)Less often
How to diagnose & fix
Work through it in order
- Check the fuse and relay for the O2 heater circuit.
- Inspect the Bank 1 Sensor 3 connector and wiring.
- Measure the sensor's heater resistance against spec.
- Replace the oxygen sensor if resistance is out of range; clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P0055?+
Can I just clear P0055?+
Related codes
Read & clear P0055 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.