Oxygen Sensor Tester and Simulator





  The ST05 provides a simple interface for test and diagnostic on any Oxygen Sensor, to quickly determine whether the sensor is defective and needs replacement. It is designed as both a stand-alone tool or as a complement to any scanner during the diagnostic process, and is compatible with all types of Oxygen sensors: Zirconium; Titanium 1 volt; Titanium 5 volt; Wide Band "dual-Cell"; and heated or unheated (1, 2, 3, 4 or 5 wires).

  The ST05 is simple to set-up and use, and provides the means for fast and accurate testing, showing the sensor's output signal in real time in a bar graph, which allows to diagnose "lazy" sensors which may not trigger DTC's but cause drivability problems. It also display cross counts on an alphanumeric, can simulates rich and lean conditions, and has a test mode to test the sensor's response time giving a Pass or Fail indication on a large display. Sensors can be tested ON or OFF vehicle, and it does not require time-consuming set-up or in-depth knowledge.


  • The sensor signal output is shown in real time on the bar graph, while a 2 digit alphanumeric display shows the sensor output cross count per second.
  • By pressing the 'Test' button and performing a snap throttle acceleration of the engine, it tests the response time of the sensor and shows a pass or fail result within seconds.
  • Two buttons allows for simulation of rich or lean conditions to monitor response of the engine control module.
  • Advanced connection detection: The ST05 automatically detects common wire misconnections like ground, heater wires, disconnected test leads, reversed polarity etc. and displays these on the alphanumeric display.
  • It only requires the connection of two probe clips to the oxygen sensor wires, and the selection of the oxygen sensor type.

Simple and flexible to use

  • Sensor can be tested on or off the vehicle
  • Does not require special setups or in depth knowledge to use
  • Provides instant readings and testing capabilities of the output of the sensor
  • Diagnoses "lazy" (slow response) sensors, which may not set DTCs, but cause drivability problems
  • Excellent preventive maintenance tool, to diagnose sensors that need to be replaced before they set DTCs or completely fail
  • Ruggerized electronics make it almost impossible to damage the instrument, even if wrongly connected
  • No software to upgrade.

Technical Specifications

  • Display:
  • 2 digits LED alphanumeric display
  • 20 segments LED bargraph with 0 to 1 Volt or 0 to 5 Volt ranges
  • Cross Count: 0.1 to 10 CPS/
  • Response test: <100 ms Pass +/- 5 ms, >100 ms Fail +/- 5 ms
  • Test leads: 2 wire piercing alligator clips, and 6.5 ft cables
  • Power Source: One standard 9 Volt alkaline battery type NEDA 1604 IEC 6F 22
  • Battery life: Approx. 25 hrs, with low battery indicator and auto power
  • Physical dimensions (including holster): 6" (H) x 4" (W)x 1.5" (D) (158 x 100 X 37 mm)
  • Weight: Approximately 14 Oz. or 406 gr. (including battery)


  • Test zirconium sensors
  • Test titanium 1 Volt sensors
  • Test titanium 5 Volt sensors
  • Test 1 to 4 wires sensors (heated and unheated)
  • Simulate rich and lean sensor output
  • Test sensor response time


  • ST05
  • Two piercing clips with 6 ft. cables
  • Protective rubber holster
  • Polypropylene carrying case
  • 1 x 9 Volt alkaline battery
  • User's Manual