The first "smog check" program in the US was implemented in 1984. It all started with the Clean Air Act of 1970. Since then, the laws have evolved to keep up with the science of pollution as well as the increasingly global problem of carbon emissions.
Smog is a term for air pollution that resembles a mixture of smoke and fog. While manufacturing and a number of environmental factors contribute to the buildup of pollution, it's clear that personal vehicles are also a major reason for this smoky fog in big cities. Smog inspections attempt to control preventable pollution, and it's important to make sure you are compliant with local regulations.
Starting in the 70s and early 80s, car manufacturers began installing onboard diagnostic systems. In addition to monitoring other systems, the diagnostics collect information about the exhaust that your car is producing. During an inspection, a technician will use this computerized information as well as other, physical signs to determine whether you are in compliance with emissions standards.
There are several ways to go about keeping your vehicle compliant. Although some vehicles make an obvious case for an inspection by the cloud of noxious smoke pouring out of the tailpipe, other problems can be less telling.
Your vehicle should be inspected by certified mechanics and technicians. Most states offer two types of inspection stations: inspection only and inspection / repair. If your car is less than three years old, repairs should not be necessary. For older vehicles with suspect emissions systems, it makes sense to have a full-service center perform the inspection as well as make necessary repairs.
It is important to know the requirements for inspections. These requirements can vary from one county to another, and there are many ins and outs as to how these requirements should be met. There are many online resources to help clear up any questions you may concern about the regulations in your particular state. It is always best to keep your inspection up-to-date to avoid extra fines and late fees. Certain exemptions are sometimes made for hybrids, electric models, and motorcycles. There may also be special provisions for cars more than 25 years old.
In most states, the DMV will send a renewal notice for registration that will tell you when smog inspections are required. You are then required to produce a smog certificate within 90 days in order to have your registration renewed. In the event of a failed test, the owner will be required to make the necessary repairs. Your registration will not be renewed until the car is compliant with state laws. The Bureau of Automotive Repair also has a financial assistance program for those in need of assistance.