W. Va. Code § 22A-2A-210: Exhaust emissions control and conditioning system defined.

"Exhaust emissions control and conditioning system" means a device or combination of devices that will collect and treat diesel exhaust emissions at the exhaust port of the engine and will reduce the volume of, or eliminate emissions of, diesel particulate matter, carbon monoxide and oxides of nitrogen in accordance with the requirements and standards of the commission established in accordance with the provisions of section four hundred three of this article.