Engine Error
P2271
O2 Sensor Signal Biased/Stuck Rich (Bank 1 Sensor 2)
Severity
Low
Symptoms
Check engine light, slight fuel economy drop
Common Causes
- Faulty downstream O2 sensor
- Fuel pressure regulator leaking fuel into vacuum line
- Rich running engine condition
- Short in O2 sensor wiring
How to Fix
- 1 Replace downstream O2 sensor
- 2 Check fuel pressure regulator
- 3 Diagnose engine rich condition (MAF, Injectors)
- 4 Repair wiring harness
Estimated Repair Cost
USD
$100
–
$350
O2 sensor: $150 - $300