This case addresses violations of the Clean Air Act (CAA) by American SD Power, Inc. ( American SD ), a generator manufacturer in Chino, California. On March 2, 2013, American SD imported 600 portable generators into the Port of Long Beach. EPA found that the generators contain engines that are capable of operating on gasoline, liquified petroleum gas (LPG), and natural gas (NG) ( Trifuel ), but the engines are not covered by a certificate of conformity (COC) for Tri-fuel. Further, a Pulse Air Injector Reactor (PAIR) system was not found on the inspected generator as represented in the certificate application. EPA also found that the generators do not have 3-Way catalytic converters ( TWC ) and the inspected gaseous fuel regulator has an adjustable parameter to adjust the fuel/air mixture. The absence of a COC for Tri-fuel operation, the absence of a TWC and a PAIR system, and the gaseous fuel regulator's capability of fuel/air mixture adjustments each have an effect on emissions. While American SD did claim that two different Certificates of Conformity (COCs) cover the subject generators, the engines contained in the subject generators were found to be uncertified because they differ materially from the design description in the application for the COC, and a COC covers only those engines that conform in all material respects to the design specifications described in the COC application. As a result, importation of the generators into the United States is prohibited by EPA