Indiana Code Title 13. Environment § 13-17-5-2

Sec. 2. Any rules proposed for adoption under section 1 of this chapter must be consistent with provisions of federal law relating to control of emissions from vehicles.  The board may not require, as a condition precedent to the initial sale of a vehicle or vehicular equipment, the inspection, certification, or other approval of any feature or equipment designed for the control of emissions from vehicles if the feature or equipment has been certified, approved, or otherwise authorized under federal law.