You don't, if the O2 sensor is giving you a code you have one of two problems. One the sensor is bad or two something mechanically is bad such as, the air filter or fuel filter is dirty, or a fuel injector is bad or your car is burning oil or the cat converter is bad or ?. If you have made recent repairs and the O2 sensor started acting up after the repair you might be able to remove the sensor and burn off what it is sensing with a lighter and then reinstall the sensor. That has worked for me in the past. Good Luck