Cal. Health & Safety Code § 43660

The state board shall review the requirement that every 1966 through 1970 light-duty motor vehicle be equipped with a certified device to control its exhaust emissions of oxides of nitrogen upon initial registration and upon transfer of ownership and registration, to determine the contribution of that requirement to the maintenance of ambient air quality standards in the state and the cost effectiveness of that requirement. The state board shall report to the Legislature its findings and recommendations with regard to the requirement not later than January 1, 1984.