AEM Digital Wideband UEGO Gauge w/o SensorA wideband UEGO sensor controller accurately monitors Air Fuel ratios (AFR) during the tuning process to prevent a lean fuel mixture, which could lead to engine damage. AEM has combined its single channel wideband UEGO controller and gauge display into one unit, uniting unsurpassed AFR accuracy and control with an easy to read interface. AEMs Gauge Type Wideband UEGO Controller features a digital LED display and sweeping LED needle that changes colors