2004 & 2005 is when it kicked in, as per the info I got just tonight. SE Muffler replacement is OK on a stock system. But you can't throw a Rhynhart or a Thunderheader collector system on the new ones without HD pulling your engine warranty.
Damn. Just damn.
H-D has had this policy for years. As long as the dealer installs the Genuine Harley-Davidson exhaust system components(And corresponding intake system components if applicable), the warranty will not be voided. Not only that, but the accessories themselves will be covered under the two-year vehicle warranty if installed at the time of purchase and included in the sales contract.
BTW, at the most recent H-D Dealer meeting in Grapevine, TX, Harley announced a new "Active Performance Exhaust Kit" with the performance characteristics of Screaming Eagle Pro race use only exhaust but with EPA and CARB approved sound and emisson levels. The catalyst equipped system utilizes an electronic servo-controlled (Yes Harvey, it has "Muffler bearings".) butterfly valve and an onboard computer. The system is 50 state street legal when used with the Screaming Eagle Stage 1 Air Cleaner Kit on stock Twin Cam engines. (ECM calibration required)
At the Winter Dealer Meeting, Harley-Davidson President, Jim McCaslin, reiterated the Motor Company's position on noise, namely that Harley-Davidson opposes modifying motorcycle exhaust systems so as to produce more noise. Its bad for the sport and bad for the industry. He said that the Motor Company will continue to develop exhaust systems and components that enhance the motorcycleing experience and preserve the unique character (Meaning the sound, one supposes) of Harley-Davidson motorcycles without increasing the noise to objectionable or illegal levels.