Not sure of your wire colors, but all you need to do with autometer a/f is the reference wire from the o2 and any switched 12v+ supply and should have an isolated ground. the reference wire can be diffrent some o2s use the voltage drop to calculate a rich or lean condidtion. some are 4 wire o2s so you will have a heater wire reference signal and either power/ground depending on the car. in that case you want the signal wire generally have a voltage of .05 to 3.9 Vdc hope that helps