Heated Oxygen Sensor Heater Resistance (Bank 1, Sensor 3)
The P0055 code means the vehicle's onboard diagnostic system has detected: Heated Oxygen Sensor Heater Resistance (Bank 1, Sensor 3). This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- easy
- Estimated cost
- $100 - $300 (parts and labor)
Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.
Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.
Affiliate links — we earn a commission at no extra cost to you.
Common Symptoms
- Check Engine Light on
- Slight decrease in fuel economy
- Extended time for O2 sensor to reach operating temperature
- Potential emissions test failure
Probable Causes (Ranked by Likelihood)
- Degraded heater element in Bank 1 Sensor 3 Very High
- High-resistance connection at sensor connector High
- Wiring damage between ECM and sensor Moderate
- Aftermarket O2 sensor with incorrect resistance Low
Frequently Asked Questions
What does P0055 mean?
P0055 indicates the heater resistance in the Bank 1 Sensor 3 oxygen sensor is outside the normal specification, typically from a worn heater element.
Do all cars have a Sensor 3?
No, only vehicles with multiple catalytic converters (usually V6 or V8 engines) have a Sensor 3 position. Four-cylinder engines typically only have Sensor 1 and Sensor 2.
Can I drive with P0055?
Yes, P0055 is low severity and does not significantly affect driveability. However, it may cause an emissions test failure.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Confirm P0055 and locate Bank 1 Sensor 3
-
Measure heater element resistance at sensor connector
-
Compare to manufacturer specification for heater resistance
-
Check wiring and connector integrity
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2008-2017 Honda Pilot
- 2010-2019 Toyota Highlander V6
- 2007-2016 Lexus ES350
- 2009-2018 Acura MDX
Related Codes
Explore More
Was this helpful?
Send this to whoever is fixing the car — your mechanic, or the person asking what the light means.