Back to all

Passing the Test (How to Prevent Emissions Test Failure)

April 25, 2021

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.

Tuffy Kentwood (Kalamazoo Ave SE)
4384 Kalamazoo Ave. SE
Kentwood, Michigan 49508
616.301.1436

More articles from Tuffy Kentwood (Kalamazoo Ave. SE)

Why Maintaining Your Windshield Wipers and Washers Matters (Windshield Wiper and Washer Inspection)

October 12, 2025

What do mud, bird droppings and frost all have in common? When theyre covering your windshield, they can temporarily obscure your view of the road, leaving you driving blind. And when you cant see the road clearly ahead of you, it can be really scary. Thats one of the reasons its important to m... More

Cabin Air Filter and Engine Air Filter: What?s the Difference?

October 5, 2025

You may have heard someone say they just got the air filter replaced in their vehicle. But did you know your vehicle has two different major air filters and they both perform quite differentbut very importantduties? Todays vehicles have a cabin air filter, and an engine air filter. The engine a... More

Knowledge is Power (Battery Testing)

September 28, 2025

Its likely happened to you once or twice. You head to your vehicle, open the door, turn the key and lo and behold, your battery is dead. Now youre stranded, may have to get a jump or a tow, and youll definitely be late for wherever you were headed. While your vehicle may sometimes give you warni... More