What Arizona emission testing requires

Arizona requires emission testing for most vehicles registered in Maricopa and Pima counties — the Phoenix and Tucson metro areas. If you live outside those two counties, you do not need an emission test to renew your registration. If you do live in one of those counties, you must pass a test every two years, and the test must happen within 90 days before your registration expires.

The test itself checks your vehicle's tailpipe emissions for nitrogen oxides, particulate matter, and other pollutants. You drive to a testing station, a technician plugs a diagnostic machine into your vehicle's onboard computer, and the results come back in minutes. The test costs between $20 and $30 depending on the station.

Vehicles from 1975 and older, electric vehicles, and vehicles registered as classic or antique are exempt. Diesel vehicles registered before 2008 are also exempt. If your vehicle fails, you have until your registration expires to repair it and retest.

Key Takeaways

  • Emission testing is required only in Maricopa County (Phoenix area) and Pima County (Tucson area); all other Arizona counties do not require it.
  • You must test within 90 days before your registration expires, and you must pass before you can renew your registration online or in person.
  • Testing stations are run by private businesses, not the state, and you can find them through the Arizona Department of Environmental Quality website or by searching for "emission testing near me."
  • If your vehicle fails, you have until your registration expiration date to make repairs and retest at any station.
  • Vehicles older than 1975, electric vehicles, and registered classic or antique vehicles do not need to test.

Finding a testing station in your area

The Arizona Department of Environmental Quality (ADEQ) maintains a searchable list of authorized emission testing stations on its website. You can search by city or ZIP code to find stations near you. Most stations are open during regular business hours, and many offer evening or weekend appointments.

You do not need to make an appointment at most stations — you can walk in during business hours. However, some stations do take appointments, and calling ahead can save you a wait, especially during busy renewal periods near the end of the month.

Bring your vehicle registration and a photo ID. The technician will need your vehicle identification number (VIN), which is on your registration and on the dashboard at the base of the windshield on the driver's side.

What happens if your vehicle fails the test

A failed test does not prevent you from driving. It only prevents you from renewing your registration. You have until your registration expiration date to have the vehicle repaired and retested.

Common reasons for failure include a faulty oxygen sensor, a loose or missing gas cap, a malfunctioning catalytic converter, or an engine light that is on. Many repair shops can diagnose the problem for $50 to $100. Once you repair the issue, you can retest at any authorized station — you do not have to return to the same one.

If repairs are expensive and your vehicle is old, you may want to get a second opinion from another shop before spending money. Some shops specialize in emissions repairs and may charge less than a dealership.

Retesting after a repair

After you repair your vehicle, you can retest when ready at any authorized station. There is no waiting period between the failed test and the retest. You will pay the testing fee again, usually $20 to $30.

Keep your failed test receipt. Some repair shops ask to see it so they know what failed. If you pass the retest, the testing station will give you a new receipt showing a passing result. Take that receipt to the Arizona Motor Vehicle Division when you renew your registration, or the station may submit the result electronically if you provide your registration information.

Renewing your registration after passing the test

Once you have a passing emission test result, you can renew your registration online through the Arizona Motor Vehicle Division website, by mail, or in person at a local MVD office. You do not need to bring the emission test receipt if the testing station submitted the result electronically — the MVD will see it in their system.

If you renewed your registration before getting a passing test, your registration will be suspended until you pass. You can restore it by submitting proof of a passing test to the MVD. If your registration has already expired and you have not yet tested, you cannot legally drive the vehicle until you test, pass, and renew.

Vehicles that do not need emission testing

Electric vehicles, hybrid vehicles, and vehicles registered as classic or antique are exempt from testing. Vehicles manufactured in 1975 or earlier do not need to test. Diesel vehicles registered before 2008 are also exempt.

If your vehicle falls into one of these categories, you still need to renew your registration, but you do not need an emission test. When you renew, the MVD will not ask for a test result.

Frequently Asked Questions

Do I need an emission test if I just moved to Arizona?

Only if you register your vehicle in Maricopa or Pima County. When you register, the MVD will tell you whether testing is required based on your county. If you move to a county that does not require testing, you do not need to test when you renew.

Can I test before my 90-day window?

No. Testing must happen within 90 days before your registration expires. If you test earlier, the result will not be valid for renewal. The testing station will tell you the expiration date of your test result when you pass.

What if I cannot find a testing station near me?

Check the ADEQ website for the full list of authorized stations in your county. If all nearby stations are booked, you can drive to a station in a different city — there is no requirement to test in your own city. Some stations have longer hours or more availability than others.

Can I test in a different county than where I live?

Yes. You can test at any authorized station in Arizona, even if it is not in your county. The test result is valid for registration renewal as long as you live in Maricopa or Pima County.

What if my vehicle has a check engine light on?

Your vehicle will likely fail the test if the engine light is on. The diagnostic machine reads the codes stored in your onboard computer, and an active code usually means a failed test. Have the vehicle scanned at a repair shop to find out what is wrong before you test.