30-4900 AEM's Wideband Failsafe Gauge provides the ability to accurately tune AFR, while actively protecting your engine by constantly monitoring AFR curves and activating a user-defined failsafe strategy if it runs lean. The Wideband Failsafe Gauge is a Universal Exhaust Gas Oxygen (UEGO—“you-way-go”) controller with an internal boost sensor, an internal data logger and a full color Organic Light Emitting Diode (OLED) display. It includes technology to activate a failsafe strategy in the event AFR falls outside of a user-defined operating window. If the AFR falls outside of the set operating window, the Wideband FAILSAFE Gauge triggers a user defined output function that can save an engine from catastrophic damage. This gauge is a must have for all tuned performance engines, either forced induction or naturally aspirated, fuel injected or carbureted. Any high performance vehicle owners who want a highly accurate AFR tuning tool with logging and a protection strategy that can save an engine from catastrophic failure will want this Failsafe device.