States That Require Smog/Emissions Tests
California, Texas, Arizona, Colorado, Connecticut, Delaware, Georgia, Idaho, Illinois, Indiana, Louisiana, Maine, Maryland, Massachusetts, Missouri, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Utah, Vermont, Virginia, Washington, Wisconsin
What Gets Tested
- Tailpipe emissions (CO, HC, NOx levels)
- OBD-II diagnostic scan (1996+ vehicles)
- Visual inspection of emissions equipment
- Gas cap pressure test
How to Prepare
- Drive your car for 20+ minutes before the test
- Make sure your check engine light is off
- Change oil and air filter if due
- Fix any exhaust leaks
- Use fuel system cleaner 1 week before test
What If You Fail?
You'll get a list of required repairs. Many states offer financial assistance programs for low-income owners ($500–$1,500 toward repairs). After repairs, you get a free retest within 30–60 days.