Smog check prices vary by location and test type, but you can expect to pay between $30 and $80 for a basic test

A smog check (also called an emissions test) costs differently depending on which state you live in, what kind of vehicle you drive, and whether your car needs a more complex test. In California, the most common state requiring smog checks, a basic test runs $30 to $50 at most testing stations. If your vehicle fails and needs a second test after repairs, you typically pay for that second test separately — another $30 to $50.

Some vehicles need a STAR test (Smog Check Referee information Program), which is more thorough and costs more. These specialized tests can run $60 to $80 or higher. You only need a STAR test if your car failed a regular test, or if you're buying a used vehicle that has failed emissions before. Not every station offers STAR testing, so you may need to drive to a referee station.

The fee you pay goes directly to the testing station, not to the state. Different stations set their own prices within state guidelines, so calling ahead to compare can save you money. Some smog stations also charge extra if they perform repairs on your vehicle after a failed test — that's a separate cost from the test itself.

Key Takeaways

  • Basic smog checks in California cost between $30 and $50 at most stations, with prices varying by location and station.
  • A second test after repairs costs the same as the first test and is charged separately.
  • STAR tests (for vehicles that failed or have a history of failure) cost $60 to $80 or more because they are more detailed.
  • You pay the testing station directly, and prices are not set by the state, so comparing stations by phone can lower your cost.
  • Repairs needed after a failed test are billed separately from the test fee itself.

When you need a smog check and how often

California requires a smog check every two years for most vehicles, or every year if your car is model year 1975 or older. You need one when you renew your vehicle registration, and you cannot complete registration without a passing test result. The test must happen within 30 days before you submit your registration renewal.

If you just bought a used vehicle, you need a smog check within 30 days of purchase — this is separate from your regular two-year cycle. New vehicles (model year current or previous year) are exempt from smog checks for the first six years of registration. Vehicles registered outside California do not need a smog check when they first move to the state, but they will need one at their next registration renewal.

What happens if your vehicle fails the test

A failed smog check means your vehicle's emissions are above the legal limit. You have 30 days from the test date to fix the problem and retest. During those 30 days, you can still drive the vehicle — the test failure does not when ready suspend your registration.

Common reasons for failure include a faulty oxygen sensor, a loose or missing gas cap, or a check engine light that is on. Many of these repairs cost $100 to $300, though some can be more expensive. After repairs, you return to the same station or a different one and pay for a second test. If the second test passes, you can then complete your registration renewal.

If you fail a second time, you may be required to take your vehicle to a STAR station (a referee station) for a third test. This test is more thorough and costs more, but it can sometimes pass a vehicle that failed at a regular station. A STAR test result is binding — if it passes, your registration can proceed even if a regular station failed you.

Where to find a smog check station

California maintains an online directory of licensed smog check stations at the Bureau of Automotive Repair website. You can search by zip code or city to find stations near you. The directory shows which stations offer STAR testing and which ones also perform repairs.

Many smog check stations are independent repair shops, but some are part of larger chains. Gas stations, tire shops, and quick-lube facilities often offer smog testing as well. Call ahead to confirm the station is open, ask about their current price, and ask how long the test takes — most take 15 to 30 minutes.

If you need repairs after a failed test, you can use the same station or take your vehicle elsewhere. You do not have to use the station that tested you for repairs. Some people get a second opinion at a different shop before spending money on fixes.

Preparing your vehicle for a smog check

Before you go to a smog check station, make sure your vehicle has been driven recently — at least 20 minutes of highway driving helps warm up the engine and can improve test results. Check that your gas cap is tight and not cracked, since a loose cap can trigger a test failure. If your check engine light is on, have the code read before testing; some codes will cause an automatic failure.

Your vehicle's oil should be at the correct level, and your battery should be in good condition. Bring your vehicle registration or proof of ownership, though most stations only need your vehicle identification number (VIN). You do not need an appointment at most stations, but calling ahead can save you a wait.

STAR tests and referee stations

A STAR test is a more detailed emissions test performed at a referee station. You need a STAR test if your vehicle failed a regular smog check twice, or if you are buying a used vehicle that has failed emissions testing before. STAR tests cost more — typically $60 to $80 — because they take longer and use more sensitive equipment.

Referee stations are run by the Bureau of Automotive Repair and are separate from regular smog check stations. You can find referee stations through the same online directory. A STAR test result is final; if your vehicle passes a STAR test, you can register it even if it failed at a regular station. If it fails a STAR test, you cannot retest for 30 days.

Frequently Asked Questions

Can I get a smog check at any station, or do I have to go to a specific one?

You can go to any licensed smog check station in California. The state does not assign you to a particular station. If you need a STAR test, however, you must go to a referee station — not all stations offer STAR testing, so check the directory first.

What if I move to a different state — do I still need a smog check?

No. Only California, New York, and a few other states require smog checks. If you move out of California, you will not need one for your new state's registration (unless that state also requires it). If you move into California from another state, you will need a smog check at your next registration renewal.

Do I have to pay for a smog check if my vehicle is very old?

Yes, but the frequency changes. Vehicles model year 1975 or older need a smog check every year instead of every two years. The cost is the same as a regular test. Vehicles model year 1974 or older may be exempt in some cases — check with your local DMV office.

What if the smog station says I need repairs but I do not want to fix my vehicle?

You cannot register your vehicle without a passing smog check. If you choose not to repair it, you cannot renew your registration. Your vehicle registration will eventually expire, and driving with an expired registration is illegal. Some vehicles that repeatedly fail can be declared gross polluters, which carries additional penalties.

Can I get a smog check before my registration expires, or do I have to wait?

You can get a smog check up to 30 days before your registration expires. The test result is valid for 30 days, so if you test too early, the result may expire before you can complete your registration renewal. Check your registration renewal notice for the exact important date.