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Smog Check Requirements & Preparation
A plain-English guide to California smog check rules. Always confirm your vehicle’s requirement on your DMV notice or the BAR website.
When is a smog check required?
| Situation | Smog check needed? |
|---|---|
| Biennial registration renewal | Generally every two years for gasoline vehicles older than 8 model years, as shown on your DMV notice. |
| Change of ownership | Generally required for vehicles older than 4 model years, with some family-transfer exceptions. |
| Bringing a vehicle into California | Generally required at initial registration. |
| Diesel vehicles | 1998 model year and newer, GVWR 14,000 lbs or less. 1997 and older are exempt. |
Common exemptions
- Electric vehicles
- Motorcycles
- Newer gasoline vehicles within their exempt model years
- Diesel vehicles of model year 1997 and older
Rules are updated by the state — see the Bureau of Automotive Repair and the DMV for the latest.
How to prepare
- Make sure the check-engine light is off.
- Don’t disconnect the battery shortly before the test.
- Warm up the engine by driving first.
- Fix any known leaks or issues beforehand.
- Bring your DMV notice and payment.
Certificate validity
A passing smog certificate is generally valid for 90 days for DMV registration purposes. The DMV receives the result electronically in most cases.
Ready for your smog check in Tracy?
Walk in during business hours or call (209) 836-3122.