How long does a smog check take?

The test itself takes about 20 to 30 minutes for a gasoline car from model year 2000 or newer, because the station reads the on-board diagnostics (OBD) computer instead of measuring the tailpipe. Older cars get a tailpipe test and can take longer. Waiting time depends on the station: call ahead, or go early on a weekday.

Key facts

• Gasoline cars from 2000 and newer get an OBD-based test in California.
• Cars from 1999 and older get a tailpipe emissions test, which takes longer.
• The result is sent to the DMV electronically as soon as the test is done.

What happens during those minutes

• Visual check of the emissions parts that should be there.
• Functional check of the check engine light and, on older cars, the gas cap.
• OBD scan of stored trouble codes and readiness monitors (2000 and newer), or a tailpipe test (1999 and older).

How to spend less time there

• Drive at least 15 to 20 minutes before the test so the engine is warm.
• Call the station and ask about the wait; many take walk-ins, some take appointments.
• Bring your DMV renewal notice (what to bring).

Next step

Find a smog check station in your cityWhat to bring to a smog check

Official sources: bar.ca.gov.

Related questions

• Where can I get a smog check near me?
• Do I need an appointment for a smog check, and are stations open on weekends?
• How long is a California smog certificate valid?
• Can I get a smog check if my registration is expired?

Last updated 2026-10-26. Station details are compiled from public listings and can change; call the shop to confirm hours and prices before you go.