can i remove the front drive shaft out of my mountaineer

It's an All-Wheel Drive vehicle with individual wheel speed sensors, a Traction Control System and a transfer case with a differential built in to it. Why would you remove the drive line? It isn't designed to run that way.

i took it out because people told me that it would help on gas. I put it back in but still dont have drive or over drive

If you have no 3rd or 4th, (I assume it just goes to neutral) you have a Transmission that failed.