Holley Wideband Oxygen Sensor 534-198 | Replacement Wideband Oxygen Sensor for early model or 2nd generation model commander 950 wide band kits. Sensors are for that specific model. Installation Notes: These sensors are designed for either early model or 2nd generation wideband controllers. The controller is identified by pigtails and a long harness that connects to the sensor. The 2nd generation series also has a short brown wire loop that is molded into the controller.