today i popped the hood and seen that there was a small hose and the back of engine i started it and the hose was sucking air and i attacted it to a small box does it go there and does it hose suppose to be free

Without seeing pictures or a schematic of which hose and which box, we can't tell.

The hose is a vacuum line and vacuum lines need to be connected to other hoses, sensor or switches.

If you connected a hose to a location that looks like it belongs and the engine runs better, then you are probably correct.

is there i way i can add a pic if so can u tell me how

Please check this thread out https://www.gmforum.com/t279711/

We have posted info on how to do this as well as other infromation that new Forum members need to be familiar with.

the small box next to the brack cylin

if not what is that box

I believe that is an accessory box. The hose looks like it belongs and if you car is running fine with it plugged in, that'* all that matters. Any hose that is disconnected from your engine and is drawing a vacuum, needs to be connected somewhere and you can usually find the correct location by moving the hose around and finding where the loose end reaches to.