You can just use the canned tunes that come on the x4. You don't need to have ford flash it back to stock. And I would recommend against that. The x4 will just save what is in the EEC as the stock tune which the car runs on. You don't know what mods are done to the car. So the canned tunes might not run at all then you can go back to what is in there now. You need to find out what injectors, MAF and fuel pump are in it now before you try to get some tunes. Maybe not the fuel pump info, I don't know if your car is a returnless fuel system.