STAR-certified smog checks in Lathrop
Smog inspections for renewals, sales, and vehicles new to California at our test-only station. Passing results go to the DMV electronically.
What a smog check covers
A California smog check inspects your vehicle’s emissions equipment and, on newer vehicles, reads the onboard computer. A passing certificate goes to the DMV electronically and is valid for 90 days.
- Renewal checks, when your DMV renewal notice says a smog certification is required
- Change-of-ownership checks, when a vehicle is sold
- Checks for vehicles being registered in California for the first time
What the test covers
- Visual Inspection Emissions control system, checked by eye
- Functional Inspection Emissions control system, tested working
- Onboard Diagnostics (OBD) Most 2000 and newer vehicles
- Tailpipe Emissions 1999 and older vehicles
Usually about 30 minutes. Passing results go to the DMV electronically.
Who needs one
Your DMV renewal notice says whether you need a smog check. Lathrop is in San Joaquin County, where the DMV requires smog checks at renewal for most vehicles.
Usually exempt: gasoline vehicles 1975 and older, diesel vehicles 1997 and older or over 14,000 lbs, and electric vehicles. Gasoline vehicles less than eight model years old pay a smog abatement fee instead.
Selling? The seller provides a valid smog certification. If the vehicle is less than four years old, the buyer pays a smog transfer fee instead.
Before you come in
- Bring the vehicle, and your DMV renewal notice if you have one
- Make sure the check engine light is off. If it’s on, get it repaired first
- Recently replaced the battery or had repairs? Drive normally for a week or two so the onboard monitors are ready
- Show your coupon before we start the test
How the visit works
- Check In Tell us why you need the test and show your coupon.
- Inspection A licensed inspector tests the vehicle.
- Result Pass: the certificate goes to the DMV electronically. Fail: you get the report showing what needs repair.
Smog check pricing
- Trucks, SUVs and vans: add $8
- 1996–1999 vehicles: $89.75
- 1995 and older: $99.75
Common questions
How long is a smog certificate good for?
90 days. The station sends it to the DMV electronically, so there’s no paper certificate to carry or mail.
How do I avoid an automatic fail?
Make sure the check engine light is off. If it’s on, get it repaired before the smog check. If you recently replaced the battery or had repairs, drive normally for a week or two first so the car’s onboard monitors are ready.
I’m selling my car. Who gets the smog check?
The seller. California requires the seller to give the buyer a valid smog certification. If the vehicle is less than four years old, no smog check is needed for the sale. The new owner pays a smog transfer fee instead.
Can I get smog and registration done in the same visit?
Yes, that’s what we’re set up for. We test the vehicle, the result goes to the DMV electronically, and we process the eligible renewal or transfer at the same counter. If the car doesn’t pass, the registration waits until it passes a retest.
Official sources
Checked against these sources on October 1, 2026.
Smog. Registration. Done.
Walk in, or book a time.