Re: 07 R6 Exhaust.
Read my FAQ, it will get you pointed in the right direction.
If you have a factory header you can take the slip on off entirely it won't really get any louder, so get whatever slip on you want, since the large box on the factory header is the muffler.
You can use dIAG mode to test the EXUP and clear codes.
07 R6, MJS Header, GYTR slip on, smog block offs, K&N, flashed ECU, PCV, AutoTune, -1/+2.