The General Technologies ST05 Oxygen Sensor Tester and Simulator provides a simple interface for test and diagnostic on any oxygen sensor to quickly determine whether the sensor is defective and needs replacement. Designed as both a stand-alone tool or as a complement to any scanner during the diagnostic process, The St05 is compatible with all types of oxygen sensors. The ST05 displays the sensors output signal in real-time in a bar graph, allowing to diagnose "lazy" sensors which may not trigger DTCs but cause drivability problems.