What is a Smog Check?

A smog check is a quick emissions test that shows your car meets California’s clean-air rules. Most cars need one every two years to renew registration, and when the car is sold.

Who’s in charge of smog checks?

California’s Bureau of Automotive Repair (BAR) runs the Smog Check program. When we test your car, the results go straight to BAR and the DMV electronically. You don’t have to mail anything.

(Big diesel trucks have a different program, run by CARB, called Clean Truck Check. That’s explained here.)

What happens during the test

1. You pull up out front and hand us your keys.
2. We check that your emissions parts are there and hooked up right.
3. We plug into your car’s computer and read what it’s reporting.
4. We send the results to the state. About 15 minutes, start to finish.

What to bring

Just your car. Your DMV renewal notice is handy but not required.

After you pass

The DMV gets your results right away. You can renew online, at the DMV, or at a AAA office if you’re a member. Your new sticker usually comes in the mail in about a week.

What makes cars fail

• A check engine light that’s on
• “Not ready” results after a dead battery or recent repair
• Aftermarket parts that aren’t CARB-approved
• Missing or disconnected emissions parts

Here’s how to avoid all of those.