When exhaust gases are produced by the internal combustion process in the engine, they exit the engine and travel to the catalytic converter. This is a component which is supposed to reduce the toxicity level in the gases. From there, the gases end up back in the engine cylinders where they get ignited again.
After the exhaust fumes leave the catalytic converter, they pass an oxygen sensor. The purpose of the oxygen sensor is to detect the amount of oxygen that exists in the exhaust fumes. Sometimes the catalytic converter will get stuck in a lean state. Once this happens, the oxygen sensor produces a lean voltage output.
If the powertrain control module detects a lean signal coming from the oxygen sensor, it activates trouble code P2272. This specifically refers to Oxygen Sensor on Bank 2 Sensor 2 as having a stuck lean signal. It is the downstream sensor which follows the catalytic converter. Bank 2 exists on the engine side that doesn’t have Cylinder 1 present.
Basically, when you have a stuck lean signal coming from this oxygen sensor, it means the exhaust fumes have too much air in them. However, you should not experience drivability problems other than a rough running engine. But you can still drive long enough to make it to an auto shop or mechanic. Just don’t wait too long or else you might eventually have drivability issues.
The common symptoms of trouble code P2272 include a Check Engine warning light turning on and a lean engine condition. Sometimes the engine may even enter a fail-safe mode to prevent any internal damage. You must figure out the cause of the problem before the fail-safe mode will go away. Some of the possible causes include shorted electrical wires, exhaust leak near the oxygen sensor, corrosive sensor wires, or bad oxygen sensor.
Do not automatically replace the oxygen sensor until you’ve verified where the problem is coming from. A lot of do-it-yourself car owners make this mistake. In many cases, there is an exhaust leak which needs to be fixed near the sensor. Not only will fixing the leak help solve the oxygen sensor issue, but it will also allow you to pass your emissions tests if applicable