WARNING: Cancer and Reproductive Harm - Replacement O2 Sensor for aRacers AF1 Wideband kit is a complete plug-and-play sensor. This is the original replacement sensor that comes with the wideband kit originally. Without a clean or functioning O2 sensor, calibrating your motorcycle can be difficult and can lead to future problems. This includes improper readout leading to incorrect adjustments and/or no readings at all. This O2 sensor comes ready to install, we recommend using anti-seize on the threads before installing. Be sure not to touch the end of the sensor during installation.