The AEM Bosch 4.2 LSU wideband Uego O2 replacement sensor is intended to replace the existing sensor that is used on the wideband air/fuel Uego controllers.The sensor has a laser etched calibrated resistor with the sensors connector body, this resistor has been specifically created for the sensor it is attached to. If this resistor is modified it will invalidate the sensors input. The sensor has been calibrated at the laboratory and is accurate to 0.1 and never requires free air calibration when used with the AEM wideband air/fuel controller.Replacement Sensor can be used with the following AEM Wideband Controllers: AEM Infinity Engine Management Systems 30-4100 - Digital Wideband UEGO Gauge 30-4900 - Wideband Failsafe Gauge 30-2310 - Inline Wideband UEGO Controller 30-2340 - 4-Channel Wideband UEGO Controller 30-2340-N - 4-Channel Wideband UEGO Controller - Nascar 30-5130 - Analog Wideband UEGO Gauge 30-5143 - Analog E85 Wideband UEGO Gauge 30-2320 - X-WiFi Wideband/EGT Controller