Hi, Sammy

What do you call an Oxygen sensor ???

- a "classical" lambdaprobe ? ( Make, model ??? )

- a "Wideband" lambdaprobe ? ( Make, Model ??? )

- a real Oxygen sensor like Figaro's : http://figaro.co.jp/en/make_html/item_2_sen_112280.html

without any model ... no chance to know what and how to measure !!!

BUT ... what you'll have to build is a simple voltmeter ... generally made with LM3914 chips ...

Alain