Just wondering. I have had lots of other types, but this is my first H-D, so I am full of questions. I have a new FLHTCUI and upgraded to the factory touring muffler that H-D offers. They are a little louder than the stock mufflers but there are times that I may want something even louder (more like what people expect from a H-D) than what I have. Are there some slipons that will allow this without causing problems with the EFI? Also, I took a 7 year warranty, will slipons void that?. What are my options, if any?