P2271 - O2 SENSOR SIGNAL BIASED / STUCK RICH BANK 1 SENSOR 2

The diagnostic code P2271 OBDII refers to the Oxygen (O2) sensor number 2 on bank 1. This sensor is intended to verify the proper operation of the Catalytic Converter (TWC). The Catalytic Converter or Catalyst reduces the tailpipe emissions.

When this fault code is stored, it is because the Powertrain Control Module (PCM) has detected that the signal from O2 sensor number 2 is stuck in rich, in other words, there is a significant lack of air in the exhaust.

• Check Engine light ON.
• The engine may experience a malfunction.

Reasons to set the P2271 OBD2 DTC P2271:

• The Oxygen Sensor may be contaminated or defective.
• The O2 Sensor circuit wiring system may be damaged.
• The fuel pressure may be incorrect.
• A fuel injector could be in bad condition.
• There may be a coolant leak from the engine.

To troubleshoot the P2271 OBDII error code, try this:

• Check for exhaust leaks. Repair them if you find any.
• Check the O2 Sensor wires and associated components for damage such as burns or wear. Repair or replace as required.
• Use a voltmeter to check the resistance of the harness connectors. The results of the readings you obtain should be compared to the manufacturer's specifications. Replace any connectors that do not meet these requirements.
• Monitor the Oxygen Sensor readings with an automotive scanner. For this test, the engine must be at operating temperature. An O2 Sensor usually has a voltage that changes between 0 and 1 volts. In this code, the voltage is stuck at 1V. Replace the Oxygen Sensor if the voltage does not change.