In Arizona, the law requiring vehicle emissions testing is determined by the Arizona Department of Environmental Quality (ADEQ). Emissions testing is required in certain areas of the state where air quality is a concern, and it is typically required for vehicles that are registered in those areas.
Currently, emissions testing is required for vehicles registered in the Phoenix and Tucson metropolitan areas, as well as in Pinal County. The testing requirements apply to gasoline-powered vehicles that are model year 1996 or newer, and diesel-powered vehicles that are model year 1998 or newer. These vehicles are required to pass an emissions test every two years in order to renew their registration. Exceptions are some hybrid vehicles, electric vehicles, and vehicles older than 25 years.
The emissions test is conducted at an emissions testing location and typically involves checking the emissions from the vehicle’s tailpipe using a dynamometer (a machine that simulates driving conditions). The vehicle is also inspected for tampered or missing emissions control equipment. If your vehicle passes the test, you will receive a certificate that must be presented when renewing your registration. If the vehicle fails the test, you will need to make the necessary repairs and have the vehicle retested before it can pass.
It is important to check the requirements on the ADEQ website for the most up-to-date information on emissions testing requirements, however they rarly change.