40 C.F.R. § 1045.2
The requirements and prohibitions of this part apply to manufacturers of engines and fuel-system components as described in § 1045.1 . The requirements of this part are generally addressed to manufacturers subject to this part's requirements. The term "you" generally means the certifying manufacturer. For provisions related to exhaust emissions, this generally means the engine manufacturer, especially for issues related to certification (including production-line testing, reporting, etc.). For provisions related to certification with respect to evaporative emissions, this generally means the vessel manufacturer. Vessel manufacturers must meet applicable requirements as described in § 1045.20 . Engine manufacturers must meet requirements related to evaporative emissions as described in § 1045.25 .
40 C.F.R. § 1045.2