In some states, such as California, you must pass a smog check before you can register your vehicle. You're also required to get a smog certificate before selling your vehicle. Newer vehicles don't cause as much air pollution as older ones. Therefore, a smog check is often not required if your vehicle is less than six years old. If you've been told that smog checks in your area are required, here's what you need to know.

Why It's Important

Poor air quality increases the risk of respiratory diseases and allergies, such as asthma and bronchitis. In states where more cars are on the road, the air quality is significantly lower than states with fewer cars. The smog program is designed to reduce the contribution that vehicles have on the air quality, since they give off a number of toxic gases, including carbon monoxide and nitrogen oxide. In order to comply with state laws, vehicles must undergo and pass a smog inspection. 

Passing a Smog Check

Many drivers worry about smog checks because failing means not being able to drive your vehicle. The good news is that there are steps you can take to increase your chances of passing a smog check the first time around. Before going in for your smog test, the smartest approach is to take your car in for full maintenance. Let your service center know that you are taking your vehicle in for a smog check soon, so that additional maintenance checks and measures can be performed. Your mechanic will change any dirty oil, check your coolant and oxygen sensor and give your car a tune-up, among other things. 

Failing a Smog Check

If you fail the smog check, you will be informed of your emissions levels and given the opportunity to correct the problem. If you took your car in for maintenance and still failed, it's wise to take your car back in and ask your mechanic to help determine the cause of your car's elevated emissions. In some circumstances, it's as simple as using a fuel additive to bring your emissions down. This involves pouring a fuel additive into your vehicles gas tank when you fuel and refuel.

Lower Emissions

Besides being necessary to pass a smog check, it's a good idea to consider taking steps to lower your emissions overall. The best way to lower your emissions is to use a more fuel efficient vehicle, such as cleaner burning gas vehicles, hybrids and electric vehicles.