40 CFR §205.168-11

1. (a)If a category of exhaust systems is found not to comply with this subpart because it has not been verified or labeled as required by § 205.169, the Administrator may issue an order to the manufacturer to cease distribution in commerce exhaust systems of that category. This order will not be issued if the manufacturer has made a good faith attempt to properly production verify the category and can establish such good faith.
2. (b)Any such order shall be issued after notice and opportunity for a hearing which will be held in accordance with title 5 U.S.C. 554.