This 12V oxygen sensor tester and simulator is designed for testing both Zirconia and Titania lambda/oxygen sensors. It is suitable for testing 1-4 wire lambda/oxygen sensors, both heated and unheated. The device can simulate rich and lean mixtures to monitor the ECU’s response. An LED display shows the crossover signal from the sensor. A wire piercing clamp is included for the positive lead, allowing for quick connection checks and confirming wire identity. Requires a 9V battery (available separately).