Plesae Help With Oxygen Sensor Sorting Out

I have a 1987 mustang GT and after rebuilding the engine I am left with a dilemma of sorting out my o2 sensors. My car has a A9L ecu installed by the previous owner and I want to replace the o2 sensors and figure out where a wire goes to. When I went to order original 1987 o2 sensors the color of the wires are different than what are on my car now. Also there is a orange wire sticking up from the bottom of the white salt and pepper shaker 10 pin connector that I am not sure where it goes to. I did some research and it seems to be a ground for the o2 heating part of the o2 sensors. When I turn the key on it is hot and reads 4.7 volts. So I thought that a positive wire showing hot should not be grounded or am I wrong. Also what o2 sensors should I order for replacements. Pictures show what I have in the car now. Any help would be greatly appreciated

Thank you for responding. I want to change out the o2 sensors because when I bought the car it had a hole in one of the pistons and was blowing raw oil through out the exhaust system. It was probably due to the nitrous kit it had which I deleted I completely rebuilt the engine. and it starts and runs fine at partial throttle but very little power past half throttle. I will hook up the wire the way you say and pull codes. After doing some more research I found that different make o2 sensors have different color wires so if I do buy new ones I shouldn't worry? Thanks again

example. Oh well that did turn out well!