The afr+ brings together two technologies within one system to make it the most powerful, user-friendly tuning device on the market.Afr+ combines an efi controller with a wideband o2 sensor and afr gauge to provide a user instant fuel trimming ability and feedback about their vehicle’s state of tune.The afr+ can handle all of your fueling needs or compliment ecu downloads and already installed efi controllers.The afr gauge allows you to know exactly how well your tune-up is performing.The efi fueling allows you to control any necessary fine tuning without spending more money or valuable time.