40 CFR §205.164

1. (a)Except as otherwise provided in these regulations, the provisions of this subpart apply to any motorcycle replacement exhaust system or motorcycle replacement exhaust system component which:
   1. (1)Meets the definition of the term “new product” in the Act; and
   2. (2)Is designed and marketed for use on any motorcycle subject to the provisions of subpart D of this part.
2. (b)The provisions of § 205.169 additionally apply to the motorcycle exhaust systems originally installed on vehicles subject to the requirements of subpart D of this part.
3. (c)The provisions of § 205.169(d)(3) additionally apply to motorcycle replacement exhaust systems manufactured after January 1, 1983 that are designed and marketed for use on motorcycles manufactured before January 1, 1983.
4. (d)Except as provided for in § 205.169, the provisions of this subpart do not apply to exhaust systems which are designed and marketed solely for use on competition motorcycles as defined in § 205.151(a)(3).
5. (e)The provisions of the subpart do not apply to exhaust header pipes sold as separate products.