Section 85.501 - General applicability(a) This subpart describes the provisions related to an exemption from the tampering prohibition in Clean Air Act section 203(a) ( 42 U.S.C. 7522(a) ) for light-duty vehicles, light-duty trucks, medium-duty passenger vehicles, heavy-duty vehicles, and heavy-duty engines. This subpart F does not apply for highway motorcycles or for nonroad or stationary engines or equipment.(b) For purposes of this subpart, the term "you" generally means a clean alternative fuel conversion manufacturer, which may also be called "conversion manufacturer" or "converter".