certified engine configuration

(A) that has been certified or verified by—

(i) the Administrator; or

(ii) the California Air Resources Board;

(B) that meets or is rebuilt or remanufactured to a more stringent set of engine emission standards, as determined by the Administrator; and

(C) in the case of a certified engine configuration involving the replacement of an existing engine or vehicle, an engine configuration that replaced an engine that was—

(i) removed from the vehicle; and

(ii) returned to the supplier for remanufacturing to a more stringent set of engine emissions standards or for scrappage.