40 C.F.R. § 1051.101
What emission standards and other requirements must my vehicles meet?
(a) You must show that your vehicles meet the following:
(1) The applicable exhaust emission standards in § 1051.103, § 1051.105, § 1051.107, or § 1051.145.
(i) For snowmobiles, see § 1051.103.
(ii) For off-highway motorcycles, see § 1051.105.
(iii) For all-terrain vehicles and offroad utility vehicles subject to this part, see § 1051.107 and § 1051.145.
(2) The evaporative emission standards in § 1051.110.
(3) All the requirements in § 1051.115.
(b) The certification regulations in subpart C of this part describe how you make this showing.
(c) These standards and requirements apply to all testing, including certification, production-line, and in-use testing.
(d) Other sections in this subpart describe other requirements for manufacturers such as labeling or warranty requirements.
(e) It is important that you read § 1051.145 to determine if there are other interim requirements or interim compliance options that apply for a limited time.
(f) As described in § 1051.1(a)(4), offroad utility vehicles that are subject to this part are subject to the same requirements as ATVs.