P2272 OBD-II Trouble Code: O2 Sensor Signal Stuck Lean Bank 2 Sensor 2

What the P2272 code means?

P2272 is an OBD-II generic code for the engine control module (ECM) detecting the O2 sensor for bank 2 sensor 2 after the catalytic convertor is stuck lean.

What causes the P2272 code?

• The O2 sensor for bank 2 sensor 2 is stuck in the lean voltage output when tested and stayed lean for a certain amount of time during ECM testing.

• The wiring or connector for the O2 sensor has corrosion in the connections causing excessive resistance.

• The exhaust has a leak in front of the O2 sensor.

• Possible shorted or crossed wires.

What are the symptoms of the P2272 code?

• The Check Engine light will be illuminated and the code is set in ECM memory as a fault.

• The ECM will turn off the Check Engine light if three drive cycles pass without another failure.

• The ECM may go into failure mode open loop fuel control on most manufacturer vehicles.

• The engine may have run lean to prevent catalyst damage.

How does a mechanic diagnose the P2272 code?

• Scans for codes and documents the code in the ECM and looks at the freeze frame data for failure.

• Checks the O2 sensor for damage to the sensor or wiring connections.

• Checks the exhaust for any leaks before the sensor.

• Tests the O2 sensor output when the engine is richened using propane.

• Removes O2 sensor and inspects for damage to sensing element from a damaged catalyst.

Common mistakes when diagnosing the P2272 code?

• Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired

• Failing to verify the failure before replacing the O2 sensor

• Not repairing any exhaust leaks in front of the sensor

How serious is the P2272 code?

Code P2272 is a code indicating the O2 sensor post catalyst on bank 2 is staying lean all the time. This is due to a defective sensor or an exhaust leak in front of the sensor in most cases. This will cause the vehicle to fail emission testing.

What repairs can fix the P2272 code?

• Replace the O2 sensor due to a deteriorated sensor output .
• Repair the wiring connector or wiring to the O2 sensor of corrosion.
• Repair the exhaust leak in front of the sensor.

Additional comments for consideration regarding the P2272 code

Code P2272 is caused most commonly from an internal failure of the circuit inside the O2 sensor. The other most common failure is from the exhaust flange leaking in front of the sensor. This introducing excessive amounts of oxygen into the exhaust and will cause the sensor to stay mostly lean all the time.

Need help with a P2272 code?

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