P0167 low

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.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$80 - $300 (parts and labor)
Test Before Replacing
AstroAI Digital Multimeter

Test O2 sensor voltage (should fluctuate 0.1-0.9V). Do not replace a $150 sensor without confirming it is actually bad first.

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Read Live O2 Data
BlueDriver Bluetooth Pro Scanner

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

Step-by-Step Diagnostic Procedure

  1. Check the O2 sensor heater fuse in the under-hood fuse box. Replace if blown.

  2. Measure heater circuit resistance at the sensor connector. Typical range is 2-15 ohms.

  3. Check for battery voltage at the heater supply wire with the key on.

  4. If fuse and wiring are good, replace the O2 sensor (heater is internal to the sensor).

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.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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