AEM X-Series Wideband UEGO AFR Sensor Controller Gauge, the ultimate tool for monitoring your vehicle's air-fuel ratio with precision accuracy. This innovative gauge features OBDII connectivity, introducing the readings into the data stream via CANBUS, (this is a must have feature for remote calibration/tuning). With its LSU4.9 wideband oxygen sensor, this gauge provides real-time, accurate AFR readings.