What Arizona's emissions test checks and who has to take it
Arizona requires an emissions test for most vehicles registered in Maricopa and Pima counties — the state's two most populated areas. The test measures what comes out of your tailpipe: nitrogen oxides, particulate matter, and hydrocarbons. A vehicle passes if it stays below the state's limits for those pollutants.
You need an emissions test every two years when you renew your vehicle registration, unless your vehicle is exempt. Vehicles registered outside Maricopa and Pima counties do not need an emissions test at all. Within those counties, exemptions include vehicles that are fewer than four model years old, vehicles over 25 years old, electric vehicles, and motorcycles.
If you buy a used vehicle in Arizona, you do not need a test before the sale. The test requirement is tied to registration renewal, not ownership transfer. However, if you move to Maricopa or Pima county from elsewhere in Arizona, you will need a test when you register your vehicle in that county.
Key Takeaways
- Arizona emissions tests are required every two years in Maricopa and Pima counties only, and are tied to your vehicle registration renewal date.
- The test measures tailpipe emissions and costs between $20 and $30 at any Arizona Department of Environmental Quality-certified testing station.
- You can take your test up to 90 days before your registration expires, so you can renew both at the same time.
- If your vehicle fails, you have 30 days to fix it and retest at no additional charge at the same station.
- Vehicles fewer than four model years old and vehicles over 25 years old are exempt from testing.
Where to find a testing station and what to bring
The Arizona Department of Environmental Quality maintains a searchable list of certified testing stations on its website. You can filter by county and city to find stations near you. Most are independent repair shops, some are part of larger chains, and a few are run by county programs. Call ahead to confirm hours and whether they accept walk-ins or require an appointment — policies vary widely.
Bring your vehicle registration or proof of ownership and a valid photo ID. The testing station 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. You do not need to bring your vehicle title or proof of insurance to the test itself, though you will need insurance to register the vehicle afterward.
The test itself takes 10 to 20 minutes. The technician will connect a probe to your tailpipe, run the engine at idle and at higher speeds, and record the results. You will receive a printed receipt showing whether you passed or failed.
Cost and timing around your registration renewal
An emissions test costs between $20 and $30 depending on the testing station. This is a separate fee from your vehicle registration renewal, which you will pay to the Arizona Department of Transportation when you renew your registration. The testing station does not collect registration fees.
You can take your emissions test up to 90 days before your registration expires. This means you can schedule your test early, pass or fail and retest, and then renew your registration all in one trip to the Motor Vehicle Division office or online. Many people do this to avoid a second trip.
If your registration expires before you have a passing emissions test, your vehicle is no longer legal to drive. You cannot renew your registration without proof of a passing test. If you are close to your expiration date and have not tested yet, schedule your test when ready.
What happens if your vehicle fails the test
A failure means your vehicle's emissions are above the state limit for at least one pollutant. You will receive a report showing which pollutants failed and by how much. Common reasons for failure include a faulty oxygen sensor, a loose or missing gas cap, a malfunctioning catalytic converter, or an engine that is running too rich (burning too much fuel).
You have 30 days from the test date to fix the problem and retest at the same station at no additional charge. The retest is free only at the station where you originally failed; if you go to a different station, you will pay the full test fee again. Keep your failure receipt to show the technician when you return.
If you fix the vehicle and retest within 30 days, you do not need to pay again. If you wait longer than 30 days, you will have to pay for a new test. After you pass the retest, you can renew your registration when ready.
Repair options after a failed test
The testing station itself does not repair vehicles — it only tests them. After you receive a failure report, you have two options: take the vehicle to a repair shop of your choice, or ask the testing station for a referral to a nearby repair facility.
Before you authorize any repairs, ask the shop for a written estimate. Some repairs are inexpensive — a gas cap costs a few dollars, and an oxygen sensor typically runs $100 to $300 including labor. Other repairs, like a catalytic converter replacement, can cost $500 to $1,500 or more. If the repair cost is very high, you may want to get a second opinion from another shop.
Arizona does not have a "fix-it ticket" program that waives the emissions requirement if you make a good-faith repair attempt. You must pass the test to renew your registration. If repair costs are prohibitive, you may need to consider whether the vehicle is worth keeping.
Emissions testing for diesel vehicles and older cars
Diesel vehicles are tested differently than gasoline vehicles. The test measures opacity — how much light the exhaust blocks — rather than specific chemical pollutants. Diesel testing stations are less common than gasoline stations, so call ahead to confirm a station near you performs diesel tests.
Vehicles manufactured before 1981 are exempt from emissions testing in Arizona. Vehicles from 1981 to the current year that are fewer than four model years old are also exempt. Vehicles over 25 years old are exempt regardless of when they were manufactured. If your vehicle falls into one of these categories, you do not need a test to renew your registration.
If you own a vehicle that is exempt, you still need to renew your registration every two years — you just do not need the emissions test component. You can renew your registration online, by mail, or in person at a Motor Vehicle Division office.
Online registration renewal and emissions test records
Arizona allows online registration renewal through the Motor Vehicle Division website if your vehicle has a passing emissions test on file. The system checks automatically — you do not need to upload the test result yourself. If your test is current and you have no other registration holds, you can renew in minutes.
The testing station reports your passing result to the state electronically within one business day. If you renewed your registration before the result was reported, you may see a delay in your new registration documents arriving. Call the Motor Vehicle Division if your registration renewal does not process within a week of your passing test.
If you need a copy of your emissions test result for your records, contact the testing station where you took the test. They keep records for at least three years and can provide a duplicate receipt or report.
Frequently Asked Questions
Can I take my emissions test before my registration expires?
Yes. You can test up to 90 days before your registration expires. This is useful because you can pass the test, renew your registration, and have both done before your current registration runs out. If you test more than 90 days early, the result may not be valid for registration renewal — check with your testing station about their specific policy.
What if I move out of Maricopa or Pima county?
If you move to a county that does not require emissions testing, you no longer need a test to renew your registration. When you register your vehicle in the new county, you will not be asked for an emissions test result. If you move into Maricopa or Pima county from elsewhere, you will need a test when you register there.
Do I need an emissions test if I buy a used car in Arizona?
No. The emissions test is required when you renew your registration, not when you buy a vehicle. If you purchase a used car in Maricopa or Pima county, you do not need a test before the sale. You will need a test when your registration renewal comes due, which is typically two years after the previous owner's last renewal.
What if my vehicle is too old or too new for testing?
Vehicles fewer than four model years old and vehicles over 25 years old are exempt. Vehicles manufactured before 1981 are also exempt. If your vehicle is exempt, you do not need a test to renew your registration, but you still must renew your registration itself every two years.
Can I renew my registration if my emissions test is expired?
No. Your registration renewal requires a current passing emissions test in Maricopa and Pima counties. If your test result is older than two years, it is no longer valid. You must take a new test and pass it before you can renew your registration. If your registration has already expired, your vehicle is not legal to drive.