[rd5150]

My 2 yr old pit bull has just started barking at the neighbors and their dogs through the privacy fence when he is outside and I am not. If anyone from my house is outside with him, he won't let out a peep, but as soon as we go in the house, his attention turns to the neighbors and starts calling them to come play.

So how do I correct a behavior that he will only express when I am not around?

 

[TooneyDogs]

When he starts you have to go out. Step between him and the other dogs. Use your Enough or Quiet command and then redirect him away from the fence. Give him an alternate behavior to do like chewing on a bone.
This isn't a quick fix and won't solve the problem 100% but, the barking should diminish significantly with consistency/practice.