Frequently Asked Questions

Walk-ins are always welcome! However, we recommend scheduling an appointment to ensure the fastest service and minimal wait time. You can call us at 707-206-0466 to schedule your appointment.

Most smog checks take approximately 20-30 minutes to complete. This includes the visual inspection, functional tests, and emissions testing. We strive to provide fast, efficient service while maintaining accuracy.

Our smog check prices start at $53.00 for most cars and trucks 2000 and newer. The certificate fee is $8.25. Please call us at 707-206-0466 for specific pricing for your vehicle.

Advance Smog is a test-only facility. We do not perform repairs, which ensures honest, unbiased test results. This is a requirement for STAR-certified stations and provides you with trustworthy emissions testing.

No—a lit Check Engine light (Malfunction Indicator Lamp) is an automatic smog test failure according to California BAR regulations. The light must be off and the issue resolved before testing. We offer ASE-certified diagnostics to identify and help resolve the problem.

STAR stations are California Bureau of Automotive Repair (BAR) certified facilities that meet the highest standards for smog testing. STAR stations are test-only facilities, meaning we provide honest, unbiased testing without offering repairs. Advance Smog is a STAR-certified test-only station.

Please bring your vehicle registration or DMV renewal notice, and a valid form of payment. Make sure your gas cap is present and secure, and that your Check Engine light is off before arriving.

The California DMV directs certain vehicles to STAR stations, including gross polluters, vehicles that have failed a previous test, and random selections for quality assurance. STAR stations provide the most thorough and accurate testing available.

Most gasoline-powered vehicles, diesel vehicles (1998 and newer weighing 14,000 lbs or less), and hybrid vehicles require smog checks. Vehicles 8 years old and newer are exempt. Electric vehicles, motorcycles, and trailers are also exempt. Sonoma County and Rohnert Park follow California state smog check requirements.

Yes—diesel-powered vehicles from model year 1998 and newer with a gross vehicle weight rating (GVWR) of 14,000 lbs or less require smog checks. Diesel testing includes a visual inspection and functional checks.

Yes—hybrid vehicles (gasoline-electric) require smog checks just like conventional gasoline vehicles, unless they are 8 years old or newer. Fully electric vehicles (EVs) are exempt from smog testing.

If your vehicle fails, we provide a detailed report explaining why. As a test-only facility, we don't perform repairs, but we can recommend trusted repair shops. After repairs, you can return for a retest. California offers financial assistance for low-income drivers through the Consumer Assistance Program (CAP).

Your smog certificate is valid for 90 days from the date of testing. Make sure to complete your DMV registration renewal within this time frame.

A gross polluter is a vehicle that fails the smog test with emissions significantly higher than the allowed standards. These vehicles may be subject to additional requirements and may qualify for financial assistance through California's repair assistance programs.