P0139
O2 Sensor Circuit Slow Response Bank 1 Sensor 2
Severity: MEDIUM
Symptoms
- Increased fuel consumption
- Unstable engine operation at idle
- Check Engine Light Illuminates
Causes
- Oxygen sensor malfunction
- Wiring harness damage
- Poor contact or corrosion in connectors
- Circuit Grounding Problems
How to Fix
- Check the condition of the oxygen sensor and its connectors
- Check the integrity of the wiring harness
- Clean contacts from corrosion
- Replace the oxygen sensor if necessary