In 1998 California State released a new smog check program. Vehicles have to be tested on Dynamometers for accurate smog pollution control. In addition to the Dynamometers testing, fuel cap testing has been added to the test procedure. All vehicles from 1975 and older are exempt from all aspect of the Smog Check program, but owners of these vehicles are required by law to keep their emissions system intact. All vehicles six years old and newer are not required to have a biennial Smog Check performed until their seventh year. However, these vehicles must have a Smog Check performed if the vehicle is sold or being registered in California for the first time.