Bypassing an oxygen sensor--also called an O2 sensor--can only be done using a dummy O2 sensor. Oxygen sensors are part of the vehicle's emissions control system and it may or may not be legal to replace the O2 sensor with a dummy sensor. If you use your vehicle for off-road racing or you are experienced with engine tuning, you may want to bypass the oxygen sensor so that you can more effectively tune the engine without worrying about throwing a system error and a check engine light code.
Raise your vehicle onto jack stands. Jack up the vehicle using the front jack point, which is normally located behind the radiator.
Place jack stands underneath the front pinch welds located underneath the front doors (underneath the vehicle) and lower the vehicle onto the stands.
Remove the electrical plug from the O2 sensors underneath the vehicle. They are normally located on the catalytic converter. There may be one before and one after the converter.
Remove the oxygen sensor from the vehicle by turning it counterclockwise with an O2 sensor removal tool.
Insert a new dummy O2 sensor and reconnect the electrical plug to the O2 sensor.
For specific information about removing the oxygen sensor in your vehicle, consult the particular vehicle's manual.