The Smog Check Program has greatly reduced air pollution created by millions of cars in California. According to the California Air Resources Board, the program removes about 400 tons of smog-forming pollutants from California’s air every day. With no surprise, the California Smog Check Test is known to be among the toughest smog tests in the U.S. Although greatly reducing pollution created from cars, the California Smog Check Program did not meet its expectations. Studies have shown that the program managed to only reduce the two main polluting emissions by only 12.3% and 9.8%.