Getting your vehicle's emissions tested can feel like a hassle, but it's an important part of keeping the air that you breathe clean and healthy. Depending on the state that you live in, this is something that you may have to do every two years or something that is only required when registering a vehicle. While some of the details around how your emissions are checked will vary between states, there are many similarities as well. If you are concerned about your vehicle's ability to pass emissions, there are steps you can take to make sure that you are as prepared as possible.
Check the Light!
Your vehicle is equipped with a warning light that will tell you if there are any trouble codes currently being stored by the computer. This light is commonly referred to as the "check engine light" (CEL), but it is also sometimes known as a "malfunction indicator lamp" (MIL). Whatever name the light goes by, if it is illuminated then your car is guaranteed to fail emissions. In fact, your car will fail if there are any stored codes or if the computer has recently been cleared. This means that you won't be able to simply clear the code without first addressing the underlying problem.
Deal with Deferred Maintenance
Your car doesn't have to be in perfect running condition to pass an emissions test, but there are a few maintenance items that can potentially result in a failure. Chief among them are extremely old or worn spark plugs. Anything that causes a misfire will result in incomplete combustion, ultimately causing unburnt fuel and other combustion products to make their way to your exhaust. This can easily cause your car to fail its emission test, forcing you to have your car retested later. Keeping up on basic maintenance will help to avoid unnecessary retests caused by easily preventable failures.
Don't Ignore Outstanding Issues
It goes without saying, but it is a mistake to bring your car in for an emissions tests if you are aware of the outstanding engine or exhaust issues. Many people bring in their car in knowing that it has one or more issues and hope for the best. Unfortunately, this almost never works out. Anything that is causing your engine to run poorly has the potential to affect your test results. If you know there is a problem, get it fixed rather than risk a retest. If you go in for a test anyway, you will still need to ultimately have the problem fixed and you will be on the hook for a retesting fee.
Don't Wait Until the Last Minute
Registration often depends on a successful emissions test. Even if your vehicle is running perfectly and showing no codes, there may be a subtle, hidden problem which can result in a failure. Getting a smog check as early as possible will give you time to deal with any repairs without putting your ability to have the vehicle registered in jeopardy.