The SAFR (Standalone Air/Fuel Ratio) tool was developed to address the need to quickly understand the state of tune on a vehicle without the hassle of welding in an O2 bung or splicing in wires to power the system. Easily installed on most motorcycles, ATVs and UTVs, the SAFR provides a simple analog gauge with a wideband O2 system that displays the vehicle's air/fuel ratio (AFR) values. The AFR readings allow a user to make sure a vehicle is running at optimum levels on the street or in the dirt. The SAFR is not intended to be a permanent installation. The unit is fully compatible with all vehicles. The SAFR works on carbureted or fuel injected vehicles. The diagnostic tool also works on 2 stroke or 4 stroke engines.