...you could use constructive criticism instead of just telling him the gauge is pointless.

The a/f gauge your are hooking up is just going to constantly jump back and forth from lean to rich. It doesn't give you an accurate reading of anything except for the fact that your o2 sensor is working (and if it wasn't working believe me you would know) so you basically don't need it.

As for hooking it up...

one wire to ground
one wire to headlight (dims it at night only)
one wire to ignition
one wire to o2 sensor

As stated above, phearable.net has an ecu pinout so you can trace down the correct o2 wire. Be advised though, your vehicle is obd1 which means you will actually have 4 wires coming off the o2 sensor...only one of them is the actual signal wire so use a multi meter and test to see which wire fluctuates voltage from 0-1v as the car is warming up (has no power without key in) and while driving will read about 0.4-0.6v.

The wideband o2 sensors work! They are able to actually tell you exactly what your a/f ratio is right down to the number (no flashy pointless lights). With a wideband you can actually tune the car with a standalone or piggyback.

Trust me on hooking up that gauge...you will want to rip it out of the car the first night you have to drive for a hour or more as the blinking light will piss you off more than anything.