yea, i'm pretty sure they have to prove a modification was the cause of the problem in order to void your warrenty.It will only void the warenty on the exhaust.
It really depends on your service center. They are the one that submits the claims. If they really want to they can get anything covered. Get in with your service advisor. ;( lolIt's not necessarily Kawi's warranty, it's the laws that govern warranties.