air fuel gauge hook up..

[BMW2ner]

I have a used auto meter air fuel gauge, so I dont have the instructions.
It has a purple wire
a black wire
and a red wire
What wire goes to what color on my o2 sensor?

[rs4pro3]

just a guese, but red=power black=ground and purple=sig. from 02 sensor

[Brew]

Don't bother hooking it up to your stock narrowband O2 sensor. Get yourself a quality wide band.

[np75]

I would make sure that it works with a wide band sensor before I did that. If it is set up to work with a narrow band O2 sensor, it probably won't work with a wideband. All you need is voltmeter to read a narrowband, but I think the wideband type needs a special controller. I do agree that the narrow band ones are not much good though. They are pretty much only good to tell you lean or rich, how lean or rich is pretty much a guessing game.