Sub, find out for sure if the CAT is different from standard to SE - simple call to the parts dept. at your local dealer should be able to tell you when they look up the part number in their computer. I have a Standard model cat that only has about 3,000 miles on it. I also have the factory pipes in premium condition. Daz would know for sure as he runs the shorty TORS - but you may get some backfiring even with the shorty TORS - the only way I know for sure to get rid of the backfiring is go back to the factory Tune - which I would never reccomend. However with the Factory long pipes the backfiring would be so muffled it would just sound like fluffy nuggets - let me know if you are interested in either - I can send you pictures as well.
Ok, I'll check it out. I am trying to tune the backfiring out for now.. We'll see how it goes. I may still revert back to a standard cat.
Now I wonder if the Cat really does help that much with HP...