AAA smog checks test whether your vehicle meets your state's air quality standards

A smog check is an emissions test that measures how much pollution your vehicle produces. The American Automobile Association (AAA) performs these tests at their member service centers in states that require them. The test itself takes about 10 to 15 minutes and costs between $30 and $80, depending on your state and vehicle type. Your state's Department of Motor Vehicles (DMV) or equivalent agency decides whether you need one — usually every two years, or when you register a vehicle for the first time in that state.

The test checks your vehicle's exhaust for nitrogen oxides, particulate matter, and other pollutants. If your car passes, you receive a certificate that you show to the DMV when you renew your registration. If it fails, you have a set period (usually 30 days) to repair the vehicle and retest. Some states allow one free retest after a failed test; others charge again.

Key Takeaways

  • AAA smog checks are emissions tests performed at AAA service centers in states that require them, and you need the passing certificate to renew your vehicle registration.
  • The test takes 10 to 15 minutes and costs between $30 and $80, depending on your state and whether your vehicle is gasoline or diesel.
  • Your state's DMV determines whether you need a smog check based on your vehicle's age, type, and registration status — not all states require them.
  • If your vehicle fails, you have a limited window to repair it and retest, and some states charge a fee for the second test while others do not.
  • You can find AAA service centers that perform smog checks by visiting AAA's website or calling your local branch, since not all locations offer this service.

Which states require smog checks and when you need one

Not all states require smog checks. California, New York, Massachusetts, Vermont, Connecticut, Maine, Delaware, Maryland, New Jersey, Pennsylvania, Rhode Island, and Washington DC have smog check programs. Some other states have county-level programs — for example, parts of Texas and Colorado require them while other areas do not. Your state's DMV website will tell you whether your vehicle needs one.

Timing depends on your state and your vehicle's age. In California, most vehicles need a smog check every two years. New vehicles (usually those less than four years old) are often exempt. If you are registering a vehicle in a new state for the first time, that state may require a smog check before you can complete registration. Some states require smog checks only when you sell or transfer ownership of the vehicle.

What happens during an AAA smog check

When you arrive at an AAA service center for a smog check, bring your vehicle registration and proof of ownership. The technician will connect your vehicle to a machine that reads your engine's computer and measures tailpipe emissions. For older vehicles without computer systems, the technician may perform a visual inspection instead.

The test itself takes 10 to 15 minutes. Your vehicle must be warmed up and in good running condition — if your check engine light is on, the test will likely fail. The machine produces a printout showing whether your emissions are within your state's limits. You receive this printout when ready, and if you pass, you can take it to the DMV or renew your registration online in states that allow it.

What to do if your vehicle fails the smog check

A failed smog check means your vehicle's emissions exceed your state's standards. The test report will show which pollutants are too high. Common reasons for failure include a faulty oxygen sensor, a clogged air filter, worn spark plugs, or a malfunctioning catalytic converter. You have a set period — usually 30 days from the test date — to repair your vehicle and retest.

After repairs, you can return to the same AAA location or any other certified smog check station to retest. Some states charge a fee for the second test; others allow one free retest. Keep your repair receipts, because some states ask for proof of repairs before allowing a retest. If you repair your vehicle but it still fails, you may be able to request a waiver from your state's DMV, though requirements vary widely.

How to find an AAA smog check location

Not every AAA service center performs smog checks. To find one that does, visit AAA.com and use their service center locator, or call your local AAA branch directly. When you call, ask whether they perform smog checks and whether you need an appointment. Some locations accept walk-ins; others require you to schedule ahead, especially during busy registration periods.

If no AAA location near you performs smog checks, your state's DMV website will list other certified inspection stations. These stations are held to the same standards as AAA locations and perform the same test. The cost may vary slightly between providers, but the test itself is identical.

Cost and what to bring

Smog check costs range from $30 to $80 depending on your state and vehicle type. Diesel vehicles often cost more to test than gasoline vehicles. Some states charge a flat fee; others charge based on your vehicle's model year or engine size. Call ahead to confirm the exact price for your vehicle.

Bring your vehicle registration and proof of ownership (your title or registration card). Your vehicle should be in good running condition — if the check engine light is on, the test will fail. Make sure your gas cap is tight and your vehicle has been driven recently so the engine is warm. If your vehicle has been sitting unused for a long time, drive it for 10 to 15 minutes before the test to allow the engine to reach normal operating temperature.

Understanding your smog check results

Your smog check report shows whether your vehicle passed or failed, and if it failed, which emissions exceeded the limit. The report lists specific pollutants: nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM). Each has a maximum allowed level set by your state's air quality board.

A passing result is valid for the length of your registration period — usually two years. You do not need to retest until your registration expires, unless you move to a different state that also requires smog checks. Keep your passing certificate in your vehicle or with your registration documents, because some states ask to see it during traffic stops or when renewing registration in person.

Frequently Asked Questions

Do I need a smog check if I just bought a used car?

It depends on your state and whether the car is already registered there. If you are registering a vehicle in a state for the first time, that state may require a smog check before you can complete registration. If the vehicle is already registered in your state, you follow the normal smog check schedule — usually every two years. Check your state's DMV website to be sure.

What if my vehicle is too old to test?

Most states exempt vehicles older than a certain year — often 1975 or earlier — from smog checks. Some states also exempt vehicles with fewer than a certain number of miles. Your state's DMV website lists the exact rules. If your vehicle is exempt, you do not need a smog check to register it.

Can I drive my car if it fails the smog check?

Yes, you can drive it while you arrange repairs. However, you cannot renew your registration until you pass the test. Some states allow you to drive on an expired registration for a short period while you complete repairs and retesting, but this varies. Contact your state's DMV to confirm how long you have.

How long does it take to get my smog check results?

You receive your results when ready after the test is complete — the technician prints them on the spot. If you pass, you can take the certificate to the DMV or renew your registration online the same day. If you fail, you have a set period (usually 30 days) to repair and retest.

What if I move to a state that does not require smog checks?

You do not need a smog check to register your vehicle in a state that does not require them. However, if you later move back to a state that does require them, you will need to pass a smog check before you can register there. The test is based on where you are registering, not where you came from.