Why do I Need to Have my Vehicle Tested for Smog Emissions?

June 1st, 2015

Smog Inspection in Sacramento, CA

California drivers may see emissions testing as a costly nuisance, but it’s in place for a good reason.

While smog may not be bad in downtown Sacramento, it has long been a big problem in the Los Angeles area, with millions of cars, fog from the ocean and neighboring mountains trapping smog close to the ground. In 1943, Los Angeles was stricken with a smog so thick that residents believed they were under a chemical warfare attack by the Japanese! The state’s first serious attempts to address air pollution began in 1947, when Governor Warren signed the Air Pollution Control Act, authorizing the establishment of air pollution offices in every county in the state.

In the early 60s, General Motors developed Positive Crankcase Ventilation, a system which cycled exhaust gases back into the engine’s intake manifold; GM offered the PCV system as an open patent to other manufacturers, and it became the first emissions control technology on cars. California, of course, had its own set of problems; in 1966, long before smog diagnostic testing equipment was a reality, California legislators were beginning to recognize that tailpipe emissions and air pollution were real problems. It was California that imposed the first exhaust emissions standards that year, and standards became more stringent with each passing year.

Over the years, the EPA came into being and automakers scrambled to meet emissions standards. Leaded fuel was eliminated, catalytic converters became standard equipment…and by the mid 70s, in an effort to comply with emissions laws, American cars were de-tuned to a point of being underpowered and hard on gas. Those days are long behind us, though, and emissions controls are now just one more part of the engine control computer’s functions. As engine technology has advanced, cars are getting great fuel economy with plenty of horsepower and lower tailpipe emissions than ever.

Today’s smog diagnostic testing in California is done every other year. Vehicles older than 1976 models are exempted from smog diagnostic testing, as are motorcycles, hybrid or electric vehicles, and vehicles under six years old. In addition, no smog diagnostic testing is required when transferring or selling a vehicle to a family member. For 1996 and newer vehicles, the test also requires a check of the engine computer for trouble codes, along with tailpipe testing.

We hope that clears up any questions that you might have about smog diagnostic testing in California. We invite you to come down to Auto Express in downtown Sacramento for emissions testing the next time your sticker needs to be renewed and take advantage of our $5 discount! 

  Posted in: Auto Repair 101