What STAR Smog is and where to find stations

STAR Smog is California's official vehicle emissions testing program, run by the Bureau of Automotive Repair. It tests whether your vehicle meets state air quality standards. STAR stations are independent repair shops certified by the state to perform these tests — they are not government-run facilities, but they follow strict state rules.

To find a STAR station near you, use the official STAR locator tool on the Bureau of Automotive Repair website (bar.ca.gov). You can search by zip code or city. The tool shows you the station's address, phone number, hours, and whether they test your vehicle type. You can also call your local smog referee office directly — they maintain current lists of active stations in your area.

Not all repair shops are STAR stations. A shop must be licensed and certified by the state to perform STAR tests. If you call a shop and they say they do smog tests but are not listed on the official locator, they may be a regular referee station instead, which operates under different rules. Stick with the official list to avoid confusion.

Key Takeaways

  • The official STAR locator on bar.ca.gov is the fastest way to find certified stations in your area, sorted by zip code.
  • STAR stations are independent repair shops, not government offices, but they must follow state testing procedures and rules.
  • Call ahead to confirm the station tests your vehicle type and ask about wait times, since some stations get busy during peak renewal months.
  • Bring your vehicle registration and proof of any recent repairs if your vehicle previously failed, because the station may need to document what was fixed.
  • Test results are reported directly to the state, so you do not need to submit paperwork yourself — the station handles that part.

What to bring and how the test works

Bring your vehicle registration and your keys. The station will run a tailpipe emissions test (and an onboard diagnostic test on 1996 and newer vehicles) to measure whether your vehicle's pollution output meets California standards. The whole process usually takes 15 to 30 minutes.

If your vehicle passes, the station prints a STAR test report and sends the results to the state when ready. You will receive a copy, and your registration will be flagged as compliant in the state system. If your vehicle fails, the station gives you a copy of the failure report, which shows what emissions are out of range. You then have 30 days to repair the vehicle and retest at any STAR station — the retest is usually free or low-cost.

Some stations charge a testing fee (typically $30 to $50), while others bundle it with repair work. Ask about the fee when you call. If you are retesting after a repair, confirm whether the station charges for the retest before you bring the vehicle in.

When you need a STAR test and renewal timing

California requires a STAR test every two years as part of vehicle registration renewal. Your registration notice will tell you when your test is due — it is usually the same month your registration expires. You must complete the test before you renew your registration with the DMV, or your registration will not be valid.

Plan ahead during peak months (August through October and January through March), when stations get busy. If you wait until the last week before your registration expires, you may face long waits or have trouble getting an appointment. Testing early gives you time to repair and retest if needed.

Some vehicles are exempt from STAR testing: new vehicles (usually the first four years), vehicles over 30 years old, electric vehicles, and vehicles registered as non-operational. Check your registration notice or call your local DMV to confirm whether your vehicle needs a test.

What happens if your vehicle fails the test

A failure means your vehicle's emissions are above California limits for one or more pollutants (usually nitrogen oxides, hydrocarbons, or carbon monoxide). The failure report lists which emissions failed and by how much. This tells a repair technician where to start looking for the problem.

Common causes include a faulty oxygen sensor, a loose gas cap, a clogged air filter, or a malfunctioning catalytic converter. You have 30 days from the test date to repair the vehicle and retest. If you repair it yourself or at a non-STAR shop, bring the vehicle back to any STAR station for the retest — the station does not need to be the same one that tested it first.

If you cannot afford repairs, some counties offer repair information programs. Ask the STAR station or your local air quality management district whether your county has a program that helps pay for emissions-related repairs. These programs vary by location and have income limits.

Differences between STAR stations and referee stations

STAR stations are the standard option for most drivers. They are independent repair shops that perform routine emissions tests and repairs. Referee stations are government-run facilities that handle special cases: vehicles that failed a STAR test twice, vehicles with tampering concerns, or vehicles that need a second opinion.

You do not choose a referee station on your own — you are referred to one by a STAR station or the Bureau of Automotive Repair if your case qualifies. Referee tests are more thorough and cost more (typically $70 to $100), but they are necessary only in specific situations. For a routine test, use a STAR station.

Preparing your vehicle before the test

A few straightforward steps can improve your chances of passing. Make sure your gas cap is tight — a loose cap is one of the most common failure causes and is free to fix. Check that your engine light is not on; if it is, have a technician read the code before testing, because the station may not test a vehicle with an active warning light.

Drive the vehicle normally for at least 20 minutes before the test so the engine reaches operating temperature. A cold engine can produce higher emissions readings. If your vehicle has been sitting unused for weeks, drive it around the block a few times first.

If your vehicle recently failed and you had repairs done, bring documentation of what was repaired. The station may ask to see receipts or work orders, especially if the repairs were expensive or involved the catalytic converter or engine computer.

Frequently Asked Questions

Can I test at any STAR station or do I have to go to a specific one?

You can test at any STAR station in California, not just one near your home. If you are retesting after a failure, you do not have to return to the same station. Use the official locator to find whichever station is most convenient for you.

What if I move to another state — do I still need a STAR test?

No. STAR testing is required only for vehicles registered in California. If you move out of state and change your registration, you will follow that state's emissions rules instead. If you move back to California, you will need a STAR test before you can register the vehicle here again.

How long does it take to get test results after I visit the station?

Results are reported to the state when ready after the test. You receive a printed copy at the station, and the state system is updated within hours. You do not need to wait for mail or call back — the results are final the same day.

Can I retest the same day if my vehicle fails?

Most stations will not retest the same day because repairs take time. You have 30 days from the failure date to repair and retest. If you made a quick fix (like tightening the gas cap), ask the station whether they will retest you the same day; some will, but it is not may provide.

What if the STAR station says my vehicle cannot be tested?

A station may refuse to test if the vehicle is unsafe to drive (bad brakes, no lights) or if it is too new or too old for STAR testing. Ask the station why and whether a referee station can test it instead. If the vehicle is unsafe, fix those issues first — the station is protecting you and other drivers.