I've started seeing that this reflash lowers fuel rail pressure and decreases performance. Can the dealers reflash your truck back to the way it was before the white smoke reflash?

 

In a word NO.Any reflash is permanent.

 

Sorry. But that`s a NO. The update changes (lowers it) the value in the controller and no updates have been released to return it back to the original value.
The TST box has a control for rail pressure and you can over ride it that way.
Other than that, your SOL

 

Is there a pressure box that would work with my xzt that would give me the original level of fuel rail pressure?

 

Just a thought here but you may borrow a Bullydog TripleDog to load and then return it back to stock. They use a generic program and do not store and reload factory programming like some say. I know because I had a reflash done several months ago and while I was there my dealer sold and installed the TripleDog in my truck for me. After running a while I decided to go back with Edge and the dealer noticed I had lost my reflash and they didn't even recognize the programming I had. I called Bullydog about it and was told straight from them that they do not store the stock program but have there own version. Just be careful because the awsome power that comes with it can be addicting.

 

223 the xzt is a pressure box