What Is a STAR Certified Smog Station, and When Do You Need One?

Open your DMV registration renewal and you might see a line saying your vehicle needs a smog check "at a STAR station." A lot of drivers have no idea what that means, and some end up at a shop that can't test their car. Here's the explanation.

What STAR means

STAR is a program run by California's Bureau of Automotive Repair (BAR). STAR stations are smog check stations that meet performance standards set by BAR, based on how accurately they test vehicles. A station has to keep meeting those standards to stay certified. Walnut Smog & Repair is a STAR Certified station, which is why you'll see the red STAR sign on our wall.

Why some cars are directed to STAR stations

The state directs a portion of vehicles to STAR stations. Some are selected because they're statistically more likely to have high emissions, based on their make, model and year. Others are chosen at random to keep the program accurate. Being directed to a STAR station doesn't mean anything is wrong with your car. It just means the test has to happen at a STAR station.

How to tell if you need one

Your DMV renewal notice will say so. If it says "Smog certification required" and mentions a STAR station, you'll need to use one. If it doesn't mention STAR, any licensed smog check station can test your car, including a STAR station like ours.

Test-only vs. test-and-repair

Some smog stations only test. Others, like Walnut Smog & Repair, can test and repair. That matters if your car fails. At a test-and-repair station, the same shop that sees the failure can diagnose it, fix it, and retest it, without you driving between businesses.

What happens at the test

• The inspector verifies your vehicle information.
• A visual inspection checks that emissions equipment is present and unmodified.
• Functional checks include the check engine light and other systems.
• Newer vehicles get an OBD test through the diagnostic port.
• Older vehicles get a tailpipe emissions test, often on a dynamometer.

If the car passes, the result is sent to the DMV electronically. Keep your paperwork anyway.

About the Consumer Assistance Program

BAR also runs the Consumer Assistance Program (CAP), which can help eligible owners with emissions repair costs or vehicle retirement after a failed smog check. Eligibility rules apply and change over time, so check the BAR website. The STAR sign in our shop lists Smog Test, CAP and Repair, so ask us about it when you come in.

Tips before you go

• Make sure the check engine light is off. If it's on, get it fixed first.
• Don't disconnect the battery or clear codes right before the test.
• Drive at least 15 to 20 minutes before you arrive so the engine is fully warm.
• Bring your renewal notice.

STAR smog checks in Pasadena

Walnut Smog & Repair is a STAR Certified station at 1323 E Walnut St #2, Pasadena. We test cars, trucks and older vehicles. See our smog check page, or call (626) 449-6252.

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