Engine Error
P0138
O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
Severity
Medium
Symptoms
Rich running condition, smell of unburned fuel, check engine light
Common Causes
- Defective downstream oxygen sensor
- Short to battery voltage in O2 wiring
- High fuel pressure
- Faulty engine coolant temperature sensor
How to Fix
- 1 Replace downstream O2 sensor
- 2 Inspect and repair wiring harness
- 3 Test fuel system pressure
- 4 Check ECT sensor readings
Estimated Repair Cost
USD
$100
–
$350
O2 Sensor replacement: $150 - $350