Zex Questions?

I recently purchased a zex nitrous kit...i have everything ran except for my TPS signaL WIRE...I DON'T KNOW WHICH WIRE OUT OF THE FOUR IS THE SIGNAL WIRE ON THE tps SENSOR...I ALSO WOULD LIKE TO KNOW WAT WOULD BE A SAFE SHOT ......AND DOES THE PURGE VALVE GO BETWEEN THE BOTTLE AND THE BOX..OR THE BOX AND THE NOZZLE.??

You only need one thread son.