Mr Smog Check is a network of test-only stations, not a repair shop

Mr Smog Check operates hundreds of testing locations across California where you can get your vehicle's emissions inspection done. The company does not repair vehicles — it only performs the smog test itself. If your car fails, you take it to a separate repair shop of your choice, then return to Mr Smog Check (or any other certified station) for a retest.

The network is one of several options in California for getting your smog check completed. You can also test at independent smog shops, dealerships, or other certified stations. Mr Smog Check's main advantage is availability — with locations in most populated areas — and the ability to schedule appointments online or walk in at many sites.

California requires smog tests every two years for most vehicles, or annually for vehicles over 8 years old. The test itself costs between $30 and $50 depending on the location and vehicle type. This fee goes to Mr Smog Check; it is separate from any repair costs if your vehicle fails.

Key Takeaways

  • Mr Smog Check tests your vehicle's emissions but does not repair it; you must find a separate repair shop if your car fails.
  • You can schedule an appointment online at most Mr Smog Check locations, or walk in during business hours at participating sites.
  • The test itself costs $30 to $50 and takes 15 to 30 minutes; you will receive a printed certificate if you pass.
  • If you fail, you have 30 days to repair your vehicle and retest at any certified station, including Mr Smog Check.
  • Mr Smog Check is one option among many certified testers in California; you can use any certified station for your initial test or retest.

How to schedule and what to bring

Most Mr Smog Check locations let you book an appointment through their website or by phone. Walk-ins are also accepted at many sites, though wait times vary. Before you go, have your vehicle registration and proof of insurance ready — you will need to show these at the counter.

Bring your vehicle keys and be prepared to stay for 15 to 30 minutes while the test runs. The technician will connect your car to a diagnostic machine that measures tailpipe emissions. You do not need to do anything during the test; the technician handles the entire process.

If your vehicle passes, you will receive a printed smog certificate on the spot. This certificate is valid when ready and satisfies California's emissions requirement. You can use it to renew your vehicle registration with the DMV.

What happens if your vehicle fails

A failed smog test means your vehicle's emissions are above California's limits. Mr Smog Check will print a failure report that shows which emissions are too high — usually nitrogen oxides, particulate matter, or hydrocarbons. This report is yours to keep and take to a repair shop.

You have 30 days from the test date to repair your vehicle and retest. During this window, you can take your car to any repair shop you choose — a dealership, an independent mechanic, or a shop that specializes in emissions repairs. The repair shop uses the failure report to diagnose what needs fixing.

After repairs, you can retest at Mr Smog Check or at any other certified smog station in California. Retests cost the same as the initial test. If you pass the retest, you receive a new certificate and your emissions requirement is met.

Certified stations versus non-certified shops

Mr Smog Check is a certified test-only station, meaning it is authorized by California to perform official smog tests. This certification is required to issue a valid smog certificate that the DMV will accept. Not all smog shops are certified — some are repair shops that happen to offer testing, and their tests may not be valid for registration purposes.

When you choose where to test, look for the "STAR" (Smog Check Test And Repair) program logo or ask the shop directly whether they are certified to issue smog certificates. Mr Smog Check locations display this certification. If you test at a non-certified location, your certificate will not be accepted by the DMV, and you will have to retest elsewhere.

Costs and what is included

The smog test at Mr Smog Check costs $30 to $50 depending on your vehicle type and location. This covers the emissions test and the printed certificate if you pass. There are no hidden fees for the test itself.

If you fail and need to retest, you pay the test fee again — typically $30 to $50. Repair costs are separate and depend entirely on what your vehicle needs. A straightforward fix like replacing a spark plug plug might cost $50 to $150; a catalytic converter replacement can cost $500 to $2,000 or more. Mr Smog Check does not charge for repairs because it does not perform them.

Some Mr Smog Check locations offer discounts for military, seniors, or first-time customers. Call your local site to ask whether discounts are available.

Timing and registration important date

Your smog certificate is valid for 30 days from the test date. During this window, you must submit it to the DMV as part of your vehicle registration renewal. If your certificate expires before you renew, you will need to retest.

California requires smog tests every two years for most vehicles. Your registration renewal notice will tell you whether your vehicle is due for a test. If you are unsure, check your registration card — it shows the expiration date. You can test up to 60 days before your registration expires, so you have flexibility in timing.

If your vehicle fails and you need repairs, the 30-day retest window gives you time to find a repair shop and get the work done. Plan ahead if you know your test is coming up, especially if your vehicle is older or has had emissions issues before.

Finding your nearest Mr Smog Check location

Mr Smog Check has locations throughout California, with the highest concentration in the Los Angeles, San Francisco Bay Area, and San Diego regions. You can find your nearest location by visiting their website and entering your zip code, or by calling their customer service line.

Each location has its own hours and appointment availability. Some are open evenings and weekends, while others operate during business hours only. If you need a quick test, check whether your nearest location accepts walk-ins and what the typical wait time is.

Frequently Asked Questions

Can I test at Mr Smog Check if my vehicle is registered out of state?

Yes, Mr Smog Check will test any vehicle. However, the smog certificate is only valid in California. If your vehicle is registered in another state, you will need to check that state's emissions requirements — many states do not require smog tests at all.

What if I fail the smog test twice?

If you fail a retest, you have another 30 days to repair and test again. There is no limit to the number of retests you can do. However, if your vehicle repeatedly fails, you may want to consult a mechanic who specializes in emissions repairs to diagnose a deeper problem.

Do I need an appointment or can I just walk in?

Many Mr Smog Check locations accept walk-ins, but appointment availability varies by site. Booking online or calling ahead is faster and guarantees your spot. Check your local site's policy before you go.

What if my vehicle is too old or too new to test?

California exempts vehicles manufactured before 1975 and some vehicles under 6 years old from smog testing. Mr Smog Check can tell you whether your vehicle is exempt when you call or visit. If you are unsure, bring your registration and ask the technician.

Can I use my Mr Smog Check certificate at the DMV right away?

Yes, the certificate is valid when ready after you pass the test. You can submit it to the DMV online, by mail, or in person as part of your registration renewal. The DMV will accept it as long as it is dated within 30 days of your renewal.