40 CFR § 86.079-33 - Changes to a vehicle or engine covered by certification.
(a) The manufacturer shall notify the Administrator of any change in production vehicles (or production engines) in respect to any of the parameters listed in § 86.079–24(a)(3), § 86.079–24(b)(1)(iii), § 86.079–24(b)(2) (iii) or § 86.079–24(b)(3)(iii) as applicable, giving a full description of the change. Such notification shall be in advance of the change unless the manufacturer elects to follow the procedure described in § 86.079–34.
(b) Based upon the description of the change, and data derived from such testing as the Administrator may require or conduct. The Administrator will determine whether the vehicle (or engine), as modified, would still be covered by the certificate of conformity then in effect.
(c) If the Administrator determines that the outstanding certificate would cover the modified vehicles (or engines) he will notify the manufacturer in writing. Except as provided in § 86.079–34 the change may not be put into effect prior to the manufacturer's receiving this notification. If the Administrator determines that the modified vehicles (or engines) would not be covered by the certificate then in effect, the modified vehicles (or engines) shall be treated as additions to the product line subject to § 86.079–32.