A/F Guage Question

[98Silver6]

On my 98 model there are 3 O2 sensors, 2 on manifolds and one after the cat.
I have A/F guage,now I got to the manifold sensor(drivers side) there are four wires going into the sensor.
Does anyone know the right wire to hook up the A/F guage I first tryed the purple one and the guage LED is all over the place.
Dose anyone have a good solution to this besides puting another O2 sensor put in.

[DarkSide666]

well i just had my a/f guage hooked me and i used the purple wire with the white strip in it and it jumps all over the place but i i tired the tan wire and its to weak to give a singnal

[98Silver6]

So I guess I need another O2 Sensor

[Tyler]

i thought you are supposed to put the a/f guage to the precat o2 sensor? that way it reads in combination of both banks