Motor vehicle emissions
Emissions from motor vehicles are a major contributor to air pollution in Colorado. The State of Colorado is a national leader in addressing climate change and air pollution control. CDPHE works to reduce air pollution from mobile sources through a variety of innovative programs.
Register a vehicle in Colorado
Emissions inspections for gasoline-powered vehicles
Emissions inspections for diesel-powered vehicles
Automobile Inspection and Readjustment (AIR) Program
Aftermarket catalytic converters
Low and zero emission vehicles (LEV/ZEV)
Tampering of emissions controls systems is prohibited