I Just noticed a black hose with a white plug in it. from the passenger side under the hood you can see the white plug with a green dot. It stops just short of the engine, it runs ontop across the bell housing toward the drivers seat. I lost it from there, will have to get it up on a rack to trace it better. or does anyone know what this is for. Thanks

 

Sounds like you are describing the front differential vent tube.

 

It could also be the vent tube coming off the 4-block on the transfer case.