Passing the Test (How to Prevent Emissions Test Failure)
September 22, 2024
Vehicle emission testing has become ubiquitous in North America and for a good reason. Clean air quality is important for the environment and all of us. Since vehicle emissions are among the main causes of air pollution, emission testing can alert you to problems in your vehicle than can be fixed so it won't needlessly pollute.
Emissions tests are looking for certain toxic gases internal combustion engines produce, such as nitrogen oxide, particulate matter, non-methane organic gases and formaldehyde. Emissions control systems reduce these gases if they are working properly.
The best way to minimize pollution is to keep those vehicle systems working properly, and periodic inspection and maintenance is the key. So if you want to make sure your vehicle will pass an emissions test, it helps to know what might go wrong.
Let's start on the easy one. Your gas cap could be loose, allowing vapors to escape into the atmosphere. The most common solution is to replace it. Or your air filter may be dirty. A dirty air filter may push your hydrocarbons pass the acceptable level.
Now to the more complicated things. The mixture of fuel and air in your engine may be tilted toward the "too much fuel" side. That could cause problems for your vehicle's catalytic converter, a device that converts toxic gases from your exhaust into less toxic pollutants.
Your vehicle has a closed system that prevents fuel tank vapors from escaping into the air; it's called the EVAP system. A technician can track down problems.
Vehicle engineers have gone to great lengths to minimize the amount of pollution your vehicle produces. Your vehicle's manufacturer recommends how frequently those systems need servicing. Keep those systems in good shape and you're likely to pass emissions tests with flying colors. Neglect them and you might find your vehicle failing an emissions test. When that happens, you'll have to get the problems repaired before you can get back on the road.
Blair's Ferry Automotive
1565 Blairs Ferry Rd.
Marion, Iowa 52302
319-447-6310
http://www.blairsferryautomotive.com
Need Service?
More articles from Blairs Ferry Automotive

Give me a Brake (Light)!
February 1, 2026
If that little brake warning light pops up on your dash, do you know what it means? Well, if you said no, you wouldn't be alone. You know it has something to do with your brakes, but exactly what? You're not sure. One of the reasons is that it could mean a lot of different things. It could be som... More

Go With the Flow (MAF Sensor Replacement)
January 25, 2026
A driver brought her vehicle into the shop the other day and told us how she was getting lousy fuel economy and that the engine was running rough. Plus, the Check Engine light was on. Our technician checked the code the engine had generated (why the Check Engine light was on) and found the prob... More

Getting Off to a Running Start (Starter Replacement)
January 18, 2026
When you start your vehicles engine, theres another motor that makes that whole process possible. Its called the starter, and its a small electric motor that gets your vehicle running. As you can imagine, its quite a chore for a little electric motor to turn over the big engine that powers you... More
