Diesel smog check

Driving a diesel truck, van or SUV? Here is what California requires and how Blaze Smog makes your diesel smog inspection quick and simple.

Diesel smog test

Diesel smog inspections, explained

Diesel drivers often ask whether their vehicle needs a smog check at all. In California the answer depends on the model year and the weight of your vehicle.

Diesel smog check rules at a glance

  • 1998 and newer light-duty diesel (14,000 lbs GVWR or less): smog check generally required
  • 1997 and older diesel: generally exempt
  • Over 14,000 lbs GVWR: generally exempt from the smog program
  • Newer vehicles: exempt for their first several model years
Not sure? Your DMV renewal notice tells you if a smog check is required. You can also call us at 424-354-6111.
blaze smog icon diesel

Diesel tips

  • Warm the engine before testing
  • Fix warning lights first
  • Keep emissions parts stock
  • Bring your registration

Diesel smog check FAQ

Many do. Diesel vehicles from 1998 and newer, with a gross vehicle weight rating of 14,000 lbs or less, generally need a smog inspection. Older diesels and heavier ones are generally exempt. Rules can change, so call us to confirm for your vehicle.

Diesel-powered vehicles from 1997 and older are generally exempt, as are heavy diesel vehicles over 14,000 lbs GVWR. Newer diesels are also exempt for their first several model years.

Diesel inspections focus on emissions-control equipment and the onboard computer, and can include a visual check of the exhaust and a check for smoke.

Yes. Walk-ins are welcome Monday to Saturday, 8 AM to 5 PM. If you drive a large or unusual diesel, call 424-354-6111 first so we can confirm we can test it.

Need a smog check? Just drive in.

No appointment needed. Open Monday to Saturday, 8 AM to 5 PM. Opening soon in the South Bay.