From the team that brought you the legendary FP3, the Vance & Hines FP4 is the most intuitive tuner on the market. View live sensor data, read and clear trouble codes, utilize a live sensor data display and access the best-in-industry support from FP4 technicians, all from your smartphone.  The Vance & Hines FP4 brings world-renowned fuel tuning and performance to your Harley-Davidson with all new features, and the same ease of use you expect from Vance & Hines.