ECU Tuning & Fuel Management - air/fuel ratio meter o2 sensor? what wires?

hey everyone just got the wiring done for the guage and it didnt work. the previous owner looks as if he took the first o2 sensor out and may have had some one delete the code so it wont show it...? but anyways i hooked it up to the second sensor and it shows no reading. should this work or does this sensor work a different way. also the second sensor has has four wires 2 black one green and one white. the white one is what i hooked it to i believe that is the wire that sends to the ECU, well at least that is what the book says.
main question: should i hook it up a different way or get a new front sensor for the sole purpose of the air to fuel meter?
thanks alot
red_sleeper

well went for a drive and it started working read about it and the second sensor doesnt work till the car warms up. so problem fixed :)

Sweet.

is this a wideband A/F gauge? how much you pay?

wide band? i dont understand its just a gauge i got off of ebay with the leds in a semi circle pattern that show lean to rich in color and uses about 3 leds widths when moving and so on.. wide band? dont know what am i lookin for?

oh ok. its not, dont worry about it.

What year and model?