ThunderMax claims to be the most powerful, self tuning fuel management system designed specifically for fuel injected Harley-Davidson motorcycles. The ThunderMax EFI system with AutoTune is purpose built to deliver uncompromised performance. It works on any bike, no matter if it is a plain stock one, has a performance exhaust, and/or performance air cleaner or any other performance upgrade installed. The AutoTune function of the ThunderMax will continually tune any fuel injected Harley engine for maximum performance. It is a Wide-Band, Closed Loop system which means it continually and automatically adjusts air/fuel ratios every time you ride, regardless of changes on the motorcycle or any ambient condition, such as temperature, barometric pressure, humidity or a change in the fuel quality. Once installed, the ThunderMax with AutoTune will fine tune the base map to your riding conditions and habits, automatically, every time you ride. With the ThunderMax you will experience easier starting, a smoother running engine, crisp and dramatically improved throttle response, increased performance at all riding levels without sacrificing fuel economy. It will also eliminate popping, spitting and backfiring for a better sounding exhaust. The ThunderMax also gives you the ability to adjust idle speed for a cooler running engine. The ThunderMax is an industry award winning product that outperforms all other tuning systems in every riding and performance category and comes with a 3 year limited warranty. Note: Installation of a ThunderMax requires an exhaust with 18mm exhaust sensor bungs as used on 2007 thru 2009 models or modification of the stock exhaust to accept 18mm O2 sensors.