O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)
The P0167 code indicates a malfunction in the heater circuit of the oxygen sensor located after the catalytic converter on Bank 2 (the side of the engine not containing cylinder #1). This sensor monitors catalytic converter efficiency. The heater circuit is essential for quick sensor warm-up during cold starts. A fault in this circuit can cause the sensor to remain cold, leading to inaccurate readings and potential emissions issues.
01. Most Common Causes
- Blown fuse for O2 sensor heater circuit
- Faulty O2 sensor (Bank 2 Sensor 3)
- Damaged wiring or connector in the heater circuit
- Corroded or loose electrical connections
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible decrease in fuel economy
- Rough idle or hesitation (less common)
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Inspect the O2 sensor heater circuit fuse and replace if blown.
Step 3: Visually inspect the wiring and connector for Bank 2 Sensor 3 for damage or corrosion.
Step 4: Test the heater circuit resistance at the sensor connector (typically 2-10 ohms). If open or shorted, replace the sensor.
Step 5: If wiring and sensor are okay, check for voltage at the heater circuit (usually 12V with key on). If missing, repair the power supply circuit.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, it is generally safe to drive short distances, but the vehicle may fail an emissions test and fuel economy could suffer. Prolonged driving may cause catalytic converter damage if the sensor fails to monitor efficiency.
How much does it cost to fix?▼
The cost typically ranges from $150 to $300, including parts (O2 sensor) and labor. DIY replacement can be cheaper, around $50-$100 for the sensor alone.