P0138
O2 Sensor Circuit High Voltage Bank 1 Sensor 2
Severity: MEDIUM
Symptoms
- Increased fuel consumption
- Unstable engine operation
- Check Engine Light Is On
- Reduced catalytic converter efficiency
Causes
- Oxygen sensor malfunction (Bank 1 Sensor 2)
- Damage to the sensor wiring harness
- Short circuit in the sensor circuit
- Exhaust leaks
- Fuel system problems (mixture too rich)
How to Fix
- Check the sensor wiring harness for damage.
- Check sensor connections and connectors
- Check the voltage in the sensor circuit
- Replace the oxygen sensor if necessary
- Check the exhaust system for leaks