Passing the Test (How to Prevent Emissions Test Failure)
June 20, 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.
Gary Knurek GoodYear
1973 Livernois
Troy, Michigan 48083
248-362-0350
Need Service?
More articles from Gary Knurek, Authorized GoodYear Dealer
10 Things That Are Lowering Your Fuel Economy
March 15, 2026
Regardless of whatever current gas prices may be, if you could use less gas, wouldnt you? Well, here are 10 things that are robbing you of better fuel economy that you can change for the better: Not enough air in your tires. Underinflated tires have a smaller rolling diameter and more res... More
Smooth Operator (Shock Absorbers)
March 8, 2026
When you are comfortably headed down the road, you may not realize how many of the imperfections in the driving surface are being smoothed out, so you hardly feel most of them. You can thank your shock absorbers for a lot of that comfort, and its important to make sure you keep your shocks in go... More
No Fuel-ing! (Fuel Filter Replacement)
March 1, 2026
Your vehicle has a few filters you might be somewhat familiar with. Theres the oil filter that removes impurities from your engines oil, and a couple of different kinds of air filters that prevent contaminants from getting into the engine and the cabin. But you may not know that your vehicle als... More