Ao Smog

Yes. Ao Smog is STAR certified with the California Bureau of Automotive Repair, so it can test vehicles the DMV directs to a STAR station, including gross polluters.

Yes. Ao Smog is licensed as a Test Only smog station. This station performs the smog test and issues the certificate. It does not do repairs, so a failed vehicle has to be fixed elsewhere and brought back.

Ao Smog is open Monday 10:30 AM to 5 PM; Tuesday 10:30 AM to 5 PM; Wednesday 10:30 AM to 5 PM; Thursday 10:30 AM to 5 PM; Friday 10:30 AM to 5 PM. Closed Saturday and Sunday. Hours can change on holidays, so call ahead if you are cutting it close.

Yes. Ao Smog accepts walk-ins, so you can drive in without booking ahead.

Ao Smog accepts Cash, Credit Card.

Ao Smog has held a BAR smog license since 2017. You can verify the license status at bar.ca.gov.

Ao Smog has not published a price on SmogCheckDeals. The Bureau of Automotive Repair puts the statewide average at $69.16 as of August 2026, about $65 for a 2000-or-newer vehicle and $73 for 1999-or-older, plus the $8.25 certificate fee. Call (707) 644-7664 for a quote.

Ao Smog does not take online bookings here, but walk-ins are welcome. Call (707) 644-7664 to check the wait.

Staff at Ao Smog speak English.

Bring the car, your registration or DMV renewal notice, and a way to pay. Most smog checks take 15 to 30 minutes, and most visits are closer to 20.

Ao Smog is a Test Only station, so it cannot do the repair. You would have the work done at a repair shop, then come back for the free retest within 30 days. California's Consumer Assistance Program covers up to $1,200 of emissions repairs for qualifying owners.

The closest alternatives in Vallejo are Brothers Marques Test Only (0.4 mi) and Brothers Marques Smog_& Repair (0.4 mi). Both are listed further up this page with their ratings and hours.