What the P2271 code means?
This code indicates the downstream O2 (oxygen sensor) on bank 1 has failed an onboard test run by the PCM (powertrain control module). Bank 1 is the set of cylinders that includes the number one cylinder.
What causes the P2271 code?
1. Contaminated or failed HO2S2 (Sensor 2).
2. HO2S2 wiring/circuit problem.
3. Fuel pressure incorrect.
4. Faulty fuel injector.
5. Engine coolant leak.
6. Faulty purge solenoid valve.
7. PCM has failed.
What are the symptoms of the P2271 code?
These could include a lean or rich condition in the engine, decreased fuel efficiency, black smoke from the tailpipe, and an illuminated service engine soon lamp.
Common mistakes when diagnosing the P2271 code:
Technicians report replacement of oxygen sensors, when lean or rich engine conditions are the cause of incorrect readings, is fairly common. Replacement of the incorrect oxygen sensor is also a possibility.
What repairs can fix the P2271 code?
1. Replace the bank 1 sensor 2 oxygen sensor.
2. Repair O2 the bank 1 sensor 2 wiring harness.
3. Replace the O2 connector.
4. Fix any exhaust leaks.
5. Repairing all other drivability codes and issues first.
6. Repair the PCM (Not a common failure).
7. Replacing or reprogramming the PCM.