AEM Digital Wideband UEGO Gauge

AEM's legendary Digital Wideband O2 AFR UEGO Gauge is a wideband UEGO air/fuel ratio controller (AFR) and gauge in one. It unites accuracy, speed and control with an easy to read, digital LED display and sweeping LED "needle" that changes colors as AFR changes from rich to lean. NOTE: The 30-4100 Wideband UEGO Gauge Controller that uses the 4.2 LSU sensor will be superseded to the 30-4110 Wideband UEGO Gauge Controller that uses the 4.9 LSU sensor in August 2014. Instructions for the 30-4100 will still be available in the Instructions tab after this change. WHAT IS A WIDEBAND UEGO AIR/FUEL CONTROLLER? AEM's Wideband UEGO (Universal Exhaust Gas Oxygen, pronounced "You-Way-Go") Controllers are powerful, cost-effective tuning tools that allow users to accurately monitor the Air/Fuel Ratio (AFR) of their engine. WHY USE A WIDEBAND AIR/FUEL CONTROLLER? Accurate AFR data is critical when tuning an engine. Running rich (very low air/fuel ratio, excessive fuel) can cause a loss in power, wh