Emissions Testing

States set up vehicle emission inspection programs because of the 1990 federal Clean Air Act. Tennessee's vehicle inspection program is only in effect in Hamilton, Rutherford, Summer, Williamson and Wilson counties. Vehicles weighing up to 10,500 pounds must be tested. If you purchased a new vehicle that has never been titled, no test is necessary. Otherwise, you will need to successfully pass the test before renewing your vehicle's registration. If your vehicle is visibly smoking or leaking exhaust, fuel, coolant or oil, it cannot be tested. In addition to the regular testing stations in each county, mobile testing is also available. For more information, visit: http://www.tn.gov/environment/air/air_emissions-testing-schedule.shtml.