O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)
The P0162 code indicates a malfunction in the oxygen sensor circuit for Bank 2, Sensor 3, which is the downstream sensor after the catalytic converter on the engine bank opposite cylinder #1. This sensor monitors the catalytic converter's efficiency. The code is set when the Engine Control Module (ECM) detects an abnormal voltage, resistance, or signal from the sensor, often due to wiring issues, a faulty sensor, or exhaust leaks.
1. Most Common Causes
- Faulty or aged oxygen sensor
- Open or short circuit in the sensor wiring
- Corroded, damaged, or loose sensor electrical connector
- Blown oxygen sensor system fuse
- Internal ECU failure (rare)
- Exhaust leak near the sensor (affecting readings)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Decreased fuel economy
- Rough idle or hesitation
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other codes.
Step 2: Visually inspect the O2 sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: Check for exhaust leaks near the sensor using a smoke machine or listening for hissing.
Step 4: Test the sensor's voltage and resistance with a multimeter; compare to manufacturer specs.
Step 5: If all else is fine, replace the O2 sensor (Bank 2 Sensor 3).
4. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but it may cause reduced fuel economy and increased emissions. It's best to fix it soon to avoid failing an emissions test.
How much does it cost to fix?▼
Typically $50-$150 for the sensor plus labor if you don't DIY. DIY cost is just the sensor, around $30-$80.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.