G'day, I'm about to order a new slip on for my cbr, but i've been warned that because of the EPA rules it could land me with a large fine. After reading FAQ of the distributor's and manufacturer's there seems to be no problem, but since the police occasionally have a tendency to slap whatever fine they can on you (based on experience) i guess it's not worth the risk. I was interested in a TBR slip on - carbon fiber with a DB killer. I get pulled over or inspected a couple times a month, hence the precautions, not due to hooning, mainly my riding route. Cheers!