a group of Harley-Davidson dealerships in Utah is getting sued by "Utah Physicians for a Healthy Environment" an environmental nonprofit for installing aftermarket exhausts without catalytic converters, allowing the modified motorcycles to spew more pollution and noise. .

the judge decided that the EPA violations portion of the case would proceed, with the nonprofit having enough evidence to make a compelling case. The group's request for a preliminary injunction against those dealerships, as well as the noise violation, however, were struck down.

The original lawsuit is from 2022 and targeted four dealerships around the Salt Lake area all owned by the same LLC. According to the original complaint, "Physicians seek to enforce Defendants’ significant, repeated, and ongoing violations of the Clean Air Act and Noise Control Act, which have been and continue to be at the expense of the health and well-being of Physicians’ members and the public at large. Defendants’ violations include: 

the removal of air and noise emission control devices in motorcycles; 

the sale and installation of aftermarket parts that defeat air and noise emission control devices in motorcycles; 

and the ownership, operation, and sale of new and used motorcycles without all of their required air emission and noise controls present and functioning as designed."

https://www.rideapart.com/news/726301/utah-harley-davidson-exhaust-install-no-catalytic-converter/