For J1850 protocol models (4-pin diagnostic port). The DynaTune is an optional fuel monitoring module designed to be used with the Dynatek Fusion EFI and Dyna 2000-HDEFI. It includes two wide band O2 sensors for precision and accurate measuring and tuning on the fly. It will enable automatic correction while you ride. Each map that is offered has pre-set AFR (Air Fuel Ratio) target values. Advanced users can change the AFR from the given baseline since they are fully adjustable; each throttle opening and RPM area. Note: Compatible with the Dynatek Fusion EFI and the Dyna 2000-HDEFI ignition & fuel injection control modules. Note: Two versions are available; this one for 01-15 H-D models featuring the J1850 protocol; the other one (available as 903349) is for 11-up HLAN (CAN-bus) equipped models with a 6-pin diagnostic port.