Del. Code tit. 7, § 6701

Any motor vehicle which is subject to inspection by the Division of Motor Vehicles, or any other duly authorized body, shall, as a condition of compliance with the inspection, pass such tests as may be required to demonstrate that the motor vehicle complies with any standards and requirements, rules or regulations for the control of air contaminants established by the Department of Natural Resources and Environmental Control which are applicable to such motor vehicle.