With the consent of the vehicle manufacturer, an engine manufacturer may deliver to that vehicle manufacturer an engine separately from its exhaust after-treatment system in accordance with the provisions laid down in Annex X to Delegated Regulation (EU) 2017/654.

Member States may authorise the temporary placing on the market, for the purposes of field testing in accordance with the provisions of Annex XI to Delegated Regulation (EU) 2017/654, of engines that have not been EU type-approved in accordance with Articles 3, 5 and 7 of this Regulation.