Utah Code Ann. § 19-1-405
(1) By following the procedures and requirements of Title 63G, Chapter 3, Utah Administrative Rulemaking Act, the Air Quality Board may make rules to:
(a) certify a motor vehicle on which conversion equipment has been installed if:
(i) before the installation of conversion equipment, the motor vehicle does not exceed the emission cut points for:
(2) A reduction in emissions under Subsection (1)(a)(ii) is demonstrated by:
Amended by Chapter 295, 2014 General Session