What’s the Purpose

Since the Clean Air Act allowed the EPA to test vehicle emissions, the smog check has become a requirement for most vehicle inspections. For many states, driver’s will not be able to register their vehicle until they pass this test. It started in 1990 when the EPA started looking for ways to combat the dangerous effects of air pollution. With the test in place, they were able to control the harmful gases being released into the atmosphere from our vehicles.

Out of the 50 states in the U.S., only California is allowed to implement it’s own emissions standards. Every other state must follow the federal standards, or they can choose to follow California’s standards. One thing to note is that the California emissions standards tend to be some of the tougher standards in the nation.


In California, certain counties may be exempt from the smog and emissions test. Along with those counties, a specific list of makes and models are also exempt from the test:

  • Gas Powered Vehicles (1975 and older)

  • Natural Gas Powered Vehicles that weigh over 14,000 lbs

  • Diesel Powered Vehicles (1997 or older OR gross weight rating of 14,000 lbs

  • Electric Vehicles

  • Motorcycles

If you do need to take the test, please have these following items present with you:

  • Driver’s license

  • Proof of insurance

  • Title

  • Registration

Once you have those items in hand, you can then head over to a station. California has four stations that’ll help you with the test in one of three ways. They’ll either provide the test, provide the repairs needed to pass the test, or they’ll provide both services. Please make sure you visit the station that best fits your situation.*

*For “gross polluters,” they will be asked to visit a STAR Station

What to Expect

Once you visit a station, they will place your vehicle through the test. If you pass, you’ll be able to officially register your vehicle and you will not have to take the test again for another two years. If you fail, you’ll be given a list of repairs needed in order for you to pass and you’ll need to take the test again. In order to drive your vehicle after a failed test, you must request a 60-day temporary operating permit (TOP) from the DMV.

Depending on the status of your vehicle, you may be qualified for the Consumer Assistance Program (CAP). This program provides financial assistance for drivers that need an emissions-related repair. Depending on the severity of your vehicle, you may be even paid to retire the vehicle from service. For more info, please visit the CAP Requirements page.

For a complete list of all the requirements needed to pass the inspection, please visit the DMV’s California Smog Check page.