This article is the example of a loud exhaust disputed in court. Its the current model used by police - seizure of the vehicle.
https://vancouversun.com/news/local-...eted-by-police
Vancouver criminal lawyer Paul Doroshenko said he’s never seen police proceed with a noise-related ticket. He believes that because people are often put-off by extreme, offensive motorcycle noise, the government needs to find a way to make related legislation work, such as an administrative scheme for punishment that would lead to a seizure rather than a violation ticket.