40 CFR § 90.615
Model year restrictions related to imported engines and equipment
June 9, 2020
The provisions of 40 CFR 1068.360 apply starting January 1, 2009. These provisions limit the importation of engines or equipment after new emission standards have started to apply if the engines or equipment were built before the emission standards took effect.
[73 FR 59182, Oct. 8, 2008]