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A Basic Guide To California Smog Regulations

Last updated 6 years ago

The Federal Clean Air Act passed by Congress in 1970 and amended since, set air quality standards across the nation.  If an area fails to meet these standards, then that area has to implement emission control strategies.  In California, there are many areas that do not meet the air quality standards set by the Act. In an attempt to meet the standards, California implemented the emissions inspection program, also known as the Smog Check program.

The Smog Check program requires that most vehicles pass the smog check test in order to be registered in California. Luckily, there are many licensed Smog Check stations throughout the state, so you can have your vehicle tested conveniently by an auto repair station you trust. Remember A-1 Auto Tech offers smog & emission diagnostics. We will also try our best to help you qualify for the Consumer Assistance Smog Repair Program or the VRRRM Program.

Meanwhile the following is a basic guide to California’s smog regulations:

  • What are the elements of a smog check? Each inspection, no matter the type of vehicle, consists of three elements: the visual inspection, functional inspection, and tailpipe emissions test.
  • How are the emissions tested? There are three types of emissions tests, all of which measure the amount of pollutants being released by the vehicle.  The Acceleration Simulation Mode 2 test (or ASM2) uses a dynamometer to test a vehicle’s emissions output. This test measures tailpipe emissions, such as carbon monoxide and nitrogen oxide.  The Two Speed Idle test (or TSI) is similar to the ASM2, but tests a vehicle’s emissions at both high and low speeds.  The On-Board Diagnostics Second Generation test (or ODB2) is used on vehicles that were registered after 1995.  This test simply uses the on-board diagnostic link connector, which tells the technician if an emissions malfunction occurred.
  • What if the vehicle fails the smog check test? There are Test-Only stations and Gold Shield stations. The former can only perform smog check tests, but cannot make repairs to vehicles that fail the test.  Gold Shield stations, however, are certified to make repairs to vehicles that fail the smog check test. If your vehicle fails the smog check test, then you may want to look into the Consumer’s Assistance Program, which helps with the cost of repairs made by a Gold Shield station. (Contact us for more information). | (650) 265-4085 |
  • Do all cars need to be tested? Most vehicles require some type of smog check. The DMV will specify the type of test your vehicle needs in the paperwork sent for your registration. Some vehicles don’t require a smog check—hybrid, natural gas powered, and certain diesel powered vehicles are exempt from smog checks, as are motorcycles. If your car was manufactured before 1975, then you are not required to have a smog check/test. Since the laws change often, it is best to contact the DMV for specifics on your vehicle.

A-1 Auto Tech Inc., in Mountain View, California, is proud to belong to the Gold Shield program. No matter what type of smog check test your vehicle needs, we have the trained technicians and equipment to test your vehicle as mandated by the State of California. As a certified Gold Shield station, we do all California State Smog and Emission Repairs. Learn about all of our A1 Auto Tech services by visiting our website or giving us a call at (650) 265-4085.


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