I'm currently running a 04B with a high flow air filter and D&D slash cut slipon pipes and the bike was mapped at the stealership and I want to switch to the Vance and Hines 2 into 1 system which is on Ebay for $399. My question is this, I understand that the mapping should be adjusted with every change of intake and exhaust but being that these pipe set ups are fairly similar in sound is there any chance that I could get away without having the mapping changed or is it not worth the risk? It may be a stupid question but someone mentioned something about me having only a "Stage 1" tune or modification in a previous post and wondered if by not going with something radically loud I can get away without any additional tuning? I have a feeling the smart answer is that I won't know until I ride the bike but at this point I still have the option of not doing the mod at all and sticking with the slipons. Any and all help will be greatly appreciated.