From the team that brought you The Fuelpak FP3, the best-selling ECU tuner in the world for Harley-Davidson motorcycles, the Vance & Hines FP4 is the most intuitive tool on the market, giving you the power to control your motorcycle’s tune, view live sensor data, read and clear trouble codes, utilize a live sensor data display, and offers best in industry support from our FP4 technicians, all from your smartphone. The Vance & Hines FP4 brings our legendary fuel tuning and performance to your 2021-2022 Harley-Davidson Touring and Softail models, with all new features, and the ease of use you expect from Vance & Hines.