Emissions testing exists to ensure your car's exhaust is meeting environmental standards. Although there are 17 states that do not require emissions testing the rest of them do and that includes the District of Columbia and Puerto Rico. Not every state has the same standards for emissions testing and they don't require them on the same schedule either, but it's very likely that your vehicle is going to be required to meet some degree of standards if you want to keep it on the road.
Your car has the potential to release some fairly dangerous chemicals in its exhaust. Emissions testing is done periodically to ensure that your catalytic converter and other safety precautions are still working properly to reduce the amount of dangerous toxins put up by your car into the environment. The standards have been developed by the EPA and vehicle manufacturers include things like a catalytic converter to help meet these standards.
Over time your catalytic converter can potentially fail on you and other problems can arise as well which will affect your vehicle's abilities to safely eliminate the toxins it produces. If your vehicle is not able to pass an emissions test you may not be able to legally drive it any longer until such time as you have achieved a passing test. With that in mind let's take a look at what exactly emissions testing is looking for, and how you can make sure that your vehicle is going to get a passing grade so you don't disrupt your driving schedule.
What Does Emissions Testing Look For?
When you go in for emissions testing the first part of the test involves what is known as an OBD test. This is when the technician will hook up an onboard diagnostic tool to your car and use it to measure the efficiency of your car's computer or ECM. The ECM is responsible for monitoring your exhaust system, your catalytic converter, and so on so it needs to be in good working order if you're going to pass an emissions test.
You'll also be subject to an exhaust gas analysis which is more thorough than an OBD scan and really gets to the core of what is being pushed out of the exhaust of your vehicle. A tool will be used to measure what comes out of your exhaust when your car is running. They're going to be looking for things such as:
- Carbon monoxide
- Carbon dioxide
- Nitrogen oxides
Not every emissions test will look for nitrogen oxides, some of them are just what is known as four gas analyzers. There's also a separate kind of analysis done for diesel exhaust which includes a measurement for soot emissions or particulate matter.
After the analysis is done it will be determined whether or not your vehicle meets EPA standards. If it does, you get a sticker that certifies you passed your emissions test and you're good to go.
Tips for Passing Emissions Test
If you're worried about passing an emissions test there are some things you can do ahead of time that are going to improve your chances and make sure you get through unscathed.
Keep Your Engine Hot: If you're looking to improve your chances of passing an emissions test make sure you do a bit of driving before you actually take the test. Take a good 20- or 30-minute drive on the highway and get your car up to speed. This will get your engine working as hot as it can which is important for maximizing your abilities to pass a test. Your engine is at its most efficient when it's running at the temperature it was designed to run at. Not every driver realizes that if they only drive on short trips in the city, they're never actually getting their engine up to speed. That means you're going to get carbon build-up and other pollutants causing problems with the catalytic converter and other parts of the exhaust system because your engine is not getting hot enough to burn them off. So, if you're on the way to your test, do yourself a favour and make sure your engine gets as hot as it can beforehand so that it burns your fuel as efficiently as it can.
Get an Oil Change: If you have old oil that's not clean any longer, this also has the potential to burn in your engine and produce more toxins in your exhaust. Make sure you have had a recent oil change before you take an emissions test which will ensure that things are burning more cleanly.
Use Fuel Additives: Not everyone is aware that fuel additives really can improve the performance of your vehicle. Their purpose is to ensure that your fuel burns more cleanly and efficiently which improves engine performance and saves you money in the long run. Part of the way they do this is by cleaning the carbon that builds up throughout your exhaust and intake.
Some brands of fuel additives include guarantees that if you use them you will pass an emissions test. CRC, for instance, includes a guarantee that their $13 fuel additive formula can pull this off for you. Online reviews really do seem to support the claim, so if you are in doubt, you should give it a try because it couldn't hurt to give yourself a bit of an edge. The company offers a double your money back guarantee if you don't pass emissions after using it.
Using a fuel additive is a simple process and all you have to do is empty a bottle of it into your gas tank the next time you fill up. Drive as normal until you're all the way through the tank of gas and then refill the tank and head out for your emissions test. The directions on the bottle will specify exactly what you need to do and it's best to follow them closely to ensure the maximum benefit from the product.
Keep Your Tires Properly Inflated: People forget this one all the time, but properly inflated tires do a good job of keeping your car running far more smoothly than you realize. They increase fuel efficiency and reduce engine strain. If your tires are not inflated all the way, they are going to cause your engine to struggle more. That can have an effect on the emissions that it produces because it's struggling to meet the demands you're putting on it. Think of how hard it is to ride a bicycle when you have a flat tire. You have to put a lot more effort in. It's the same with your car when the tires are running a little flat.
Keep an Eye on the Check Engine Light: Many drivers learn to ignore their check engine light after a while. It seems to come on for all kinds of reasons, and if the vehicle doesn't seem to be performing poorly we get the urge just to ignore it because we don't even know why it came on in the first place. That is the big problem with a check engine light, it's very vague and could indicate literally hundreds of different problems. For that reason, not every driver is going to be on top of getting their car checked out when it comes on. But if you have to do an emissions test soon it's in your best interest to find out why the check engine light popped on just in case it will have an effect on the emissions test and your ability to pass it. At the very least you'll figure out why it came on in the first place, it could be a serious issue that you need to get checked out.
What Happens If I Fail My Emissions Test?
Assuming you did everything you could to prevent yourself from failing emissions testing this hopefully will not be a concern for you. However, it may happen that when you do take the test something goes wrong and you are not able to pass. What now?
If you fail an emissions test the DMV will no longer allow you to register the vehicle. That will mean it's not legal for you to have it on the road any longer. You're not allowed to have plates put on a car, and if you get caught driving it you could face some very steep fines as a result.
You will get a complete report after a failed emissions test about what exactly it was that prevented you from passing. You'll be able to use this to figure out what you need to do to get it fixed and then go back for additional testing so that you are able to get a passing grade later on.
Depending on where you live it's possible that you can get a follow-up test done free of charge in an effort to prove that you are able to pass emissions tests at this point. You really need to check with your local DMV to find out if they will do that or not because it's not a standard across every state by any means.
In general you're only looking at somewhere between $15 and $25 to get an emissions test done in the first place, so it certainly won't break the bank to have to pay for a retest but it's definitely better to get one for free rather than have to pay to do it again anyway. Many of the places that do emissions testing are trying to be competitive so it may not be too hard to find one that's willing to do a free retest after you've done your initial test.
There are a number of potential causes for a failed emissions test, but the most common ones typically include things like:
- A faulty fuel injector
- A problem with your catalytic converter
- A vacuum leak somewhere in the system
- A bad air injection system
- An issue with your ignition system
- An oxygen sensor malfunction
You'll definitely want to check out the fuel injector, the oxygen sensor, and the catalytic converter if you do fail. Those probably account for the vast majority of all failed emissions tests with the oxygen sensor being one of the main ones. A failing oxygen sensor can send incorrect signals to your car's computer which will cause it to burn fuel incorrectly. That results in higher emissions and it could simply be fixed with a matter of either cleaning or replacing the sensor. All things being equal, if you fail an emissions test and oxygen sensor is one of the best outcomes for being the cause of the problem because it's a quick and easy repair job for the most part. It could potentially cost you upwards of $250 to $500 to get this repaired so it's not necessarily a cheap one, But it's definitely one that you'll need to have done if it's the root of your emissions test problem because he won't be able to drive your car again until you pass.
It's also worth noting that, depending on where you live, if you fail to pass an emissions test and have attempted any relevant repairs but you are still unable to do so you could potentially get a waiver that omits you from having to meet emission standards any longer. But you will need to show that you are trying to get your car up to EPA standards.
The Bottom Line
If you live in a state that requires emissions testing it can be a bit of a hassle to have to go through the process, especially if you do fail. Just remember that emissions testing really is important for making sure your vehicle is running as efficiently as a can which saves you money in the long run. As well, it's good for the environment and that helps everyone out. So, for all the trouble it seems like, it really is a good thing to make sure you're able to pass emissions.
Follow our tips for getting your car through emissions with a passing grade, and make sure you're keeping up with routine maintenance so that your engine is always running the best that it can and you shouldn't have any problems with your next emissions test.