Not right away, and not for everything...removing any cats from the system will raise question with the service advisor/manager. So if you have any CELs related - or can be attirbuted to the mod - then you run a higher likely hood of being denied warranty service.
Really, if you are looking for performance - you'll need to have all cats removed a tune done. Do that, kiss goodbye to the warranty on the power and drivetrain. If you just want looks/sound, just get an 'axle back' kit...