Smog Busters


  • Smog Tests/Smog Checks
  • Gross Polluters
  • Out of State Smog
  • Motorhomes
  • Registration Renewals
  • Change of Ownership
  • Diesel

Smog Test Requirements

Consumer Tips

The Smog Busters recommend the following maintenance tips to ensure your vehicle is operating cleanly to pass the state-mandated Smog Check. SMOG Busters offers Test-Only Smog Checks at its facility in Roseville. A local DMV office will issue vehicle registration stickers once your vehicle has passed the Smog Check.


Make sure your tires are in good condition and properly inflated. Make sure the "check engine" light or any other dashboard warning lights are NOT on. Make sure that your vehicle has no fluid leaks and no safety issues. Remember, your vehicle will be strapped down on a dynamometer and required to perform flawlessly under stressful conditions.

Vehicle Preparation

Don't change the size of the tires from the original specifications. The dynamometer test equipment is calibrated to the "stock" tire size. Over- or under-sized tires will alter the speed calculations performed by the test equipment and may prevent your vehicle from going through the test since the machine won't sense the correct speed for your vehicle's tire size. Make sure your vehicle has a clean air filter and fresh engine oil.

Make sure your vehicle's gasoline cap fits your vehicle, isn't damaged and is turned tightly in place. A vehicle without a gas cap is an automatic Smog Check test failure. The week of the Smog Check test, take the vehicle out for an extended drive, preferably on the freeway and especially if you're regularly a "short trip" driver. Drive approximately 15 minutes or longer at varying speeds.