O2 Sensor Heater Circuit (Bank 2, Sensor 3)
The P0167 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Heater Circuit (Bank 2, Sensor 3). This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- easy
- Estimated cost
- $80 - $300 (parts and labor)
Test O2 sensor voltage (should fluctuate 0.1-0.9V). Do not replace a $150 sensor without confirming it is actually bad first.
Shows real-time O2 sensor readings on your phone. See if the sensor is lazy, stuck, or actually working before spending money.
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Common Symptoms
- Check Engine Light illuminated
- Longer time for O2 sensor to reach operating temperature
- Slightly higher cold-start emissions
- No noticeable driveability issues
Probable Causes (Ranked by Likelihood)
- Failed O2 sensor heater element Very High
- Blown O2 sensor heater fuse High
- Damaged wiring to heater circuit Moderate
- PCM heater driver circuit failure Low
Frequently Asked Questions
What does the O2 sensor heater do?
The heater brings the O2 sensor to operating temperature (about 600F) quickly after engine start. Without it, the sensor relies on exhaust heat, which takes much longer.
Can I drive with P0167?
Yes, this is a low severity code. The engine will run fine once the sensor warms up naturally from exhaust heat. However, it will fail an emissions test.
Is the heater a separate part from the sensor?
No, the heater element is built into the O2 sensor. If the heater fails, the entire sensor must be replaced.
What actually makes the computer set an oxygen sensor code?
The OBD II regulation requires four separate detections for an oxygen sensor (Title 13 CCR 1968.2, section (e)(7.2)): deterioration in voltage, response rate or amplitude that would push emissions past 1.5 times the FTP standards; loss of circuit continuity; out-of-range values; and the case where the sensor has degraded enough that the fuel system stops using it and falls back to open loop. A sensor can therefore set a code while still producing a signal that looks plausible on a scan tool. This is the threshold the monitor is designed around, not a description of your specific fault — the regulation says what the system must detect, not how to find it on your vehicle.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Check the O2 sensor heater fuse in the under-hood fuse box. Replace if blown.
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Measure heater circuit resistance at the sensor connector. Typical range is 2-15 ohms.
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Check for battery voltage at the heater supply wire with the key on.
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If fuse and wiring are good, replace the O2 sensor (heater is internal to the sensor).
Sources 3
This page is built from documented references. Verify against your own service info before repair work.
- California Code of Regulations, Title 13 section 1968.2 (OBD II)malfunction criteria, section (e)
- 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
- 2010-2020 Ford F-150 (5.0L V8)
- 2012-2019 Chevrolet Silverado (6.2L V8)
- 2008-2018 Toyota Tundra (5.7L V8)
- 2011-2020 Ram 1500 (5.7L HEMI)
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