(a) The recall provisions of 40 CFR part 1068, subpart E, apply instead of the provisions of this subpart for heavy-duty motor vehicles and heavy-duty motor vehicle engines regulated under 40 CFR part 86, subpart A, and 40 CFR parts 1036 and 1037. The provisions of this subpart apply for other motor vehicles and motor vehicle engines.

(b) For the purposes of this subpart, except as otherwise provided, words shall be defined as provided for by sections 214 and 302 of the Clean Air Act, 42 U.S.C. 1857, as amended.