40 CFR § 205.173-2
Tampering
June 9, 2020
The manufacturer must include the following statement pursuant to §205.173-4 with each product of that category the manufacturer distributes into commerce:
Tampering Prohibition
Federal law prohibits any modification to this exhaust system which causes the motorcycle to exceed the Federal noise standard. Use of the motorcycle with such a modified exhaust system is also prohibited.
Acts likely to constitute tampering include removal or puncturing the muffler, baffles, header pipes, or any other component which conducts exhaust gases.
[45 FR 86718, Dec. 31, 1980, as amended at 47 FR 57723, Dec. 28, 1982]