Smog inspections are often required by law, and failing to get your car inspected or failing the inspection can result in fines or other penalties. However, the fees paid for smog checks and possible repairs or adjustments required to help a car pass the smog test are separate and one does not guarantee or affect the other.
Contact your local Department of Motor Vehicles (DMV) or smog check station for more information about the rules and regulations in your area.