i am gonna buy one of those lean/stoich/rich gauges to help me when i change my fuel pressure, but I realize that I havent the slightest clue on what they hook up to or how to install them....
Honestly I don't like them. I have one, not installed anymore. It really is a useless piece of junk. Reading your plugs is the most accurate way to see how your motor is doing. Only good a/f monitor would be a wideband unit, and they are really expensive. But if you do decide to install it I believe it is the black wire you splice into.
Hey at least when you drive down the road at night you have some new lights glowing!
theres two white wires and one black wire that comes off your o2 sensor. you hook the one wire from the gauge to the black wire on the o2sensor, and the other two wires from the gague goto a 12v source and ground.
i bought the summit one, totally digital. even if its ghetto it was only 30 bucks. The guy on the phone said it was just as good as the nordskog one with the lifetime guarentee.