I wil soon have time to work on my XF that ived had for three yrs, coming off my second deployment in three years and wanna mess with my baby! Im contemplating a new exhaust for the XF. My idea is to remove the rear cats and run a single pipe to the stock exhaust. I also want to open the muffler and remove all the insulation and the perforated kidney things inside then wrapping the muffler in sound heat/deading material . I am wondering of the possible negative effects on it. Is it goin to mess with the engine at all (backpressure). Im lookin for a deeper sound out of the exhaust. Thoughts and experience much appreciated! Some other mods i wanna do are a CAI ,Eurocharged Tune, Injectors, NK plugs and Magnecor 8mm wires. Ay ideas about HP gain with these!