Bosch LSU 4.2 Wideband O2 SensorThe Bosch LSU 4. 2 Wideband O2 Sensor supports closed loop O2 maintaining optimal fuel delivery by delivering accurate measurements of the engine's air fuel ratio to the ECU in real time, determining the lambda value. Fuel Compatibility: The Bosch LSU 4. 2 WB O2 sensor is compatible with unleaded gasoline, ethanol gasoline blends, methanol, and diesel. However, the sensor's lifespan is significantly reduced when used with leaded fuel, diesel, or in 2