Emissions testing regulations can be confusing. Let us answer your questions.

Smog and emissions testing regulations were put in place by the EPA to cut down on pollution and promote fuel efficiency. Though specific policies vary throughout the country, the basics remain the same: in order to renew your license, you must regularly test your vehicle to prove you are in compliance.

In Missouri, emissions testing is regulated through the Gateway Vehicle Inspection Program (GVIP). You probably have a GVIP sticker on your windshield right now, saying your car has been inspected in accordance with state policies.

Law requires that you get you vehicle tested. But there’s an incentive for you, too. See, if your emissions and exhaust systems are working as intended, it means your car is burning fuel more efficiently. This is good for the environment because it reduces pollution, and it’s good for you because it saves you gas money.

What is a smog and emissions test, anyway?

Your engine produces harmful gases and pollutants. But you probably already knew that. What you might not know is that your car has an exhaust system in place to transform harmful pollutants into less harmful exhaust fumes.

Here’s how it works. As your engine produces pollutants—such as hydrocarbons, carbon monoxide and nitrogen oxides—and the fumes are collected in the manifold, which is basically a funnel designed to capture harmful gases and funnel them through the exhaust system.

Then the gases travel to the catalytic converter, which chemically changes harmful pollutants into less harmful gases. Nitrogen oxide becomes nitrogen gas. Hydrocarbons and carbon monoxide become water vapor and carbon dioxide. These gases—which are proven to contribute less to smog and ozone depletion—are then routed away from your car via the tailpipe.

So that’s how your exhaust system works to reduce pollution. Pretty cool, right? Well, the smog and emissions test is just a quick check to make sure all the components of your exhaust system are working as intended.

In Missouri, technicians test your vehicle’s emission control system by attaching the state-mandated testing equipment to your car’s computer. This equipment will test the sensors to make sure everything is working as designed by the vehicle’s manufacturer. For more information on car diagnostic testing and equipment, click here.

How often do I need to have my car tested?

At least every two years when you renew your license or any time there’s been a title change. Another thing: even model year cars must be tested on even-number years, and vice versa with odd model year cars. New Vehicles that are two years old with less than 40,000 miles are exempt.

Let’s say, for example, you bought a new 2017 car. The next time you would need to get an emissions test would be in 2019. But, if you sell it in 2018, you—or the buyer—would need to have it inspected before transferring the title.

Basically, your car needs to be tested for smog and emissions every two years or any time the vehicle changes hands.

Where can I find certified emissions testing technicians?

Lots of places. Here’s a list of locations provided by GVIP. But you need to choose a reputable repair facility and technician who will take care of your car—and you.

Telle Tire & Auto Centers is that repair facility. For more 82 years and four generations, St. Louis car owners have trusted us to provide the highest quality repairs and customer service.

What if I failed my smog and emissions test?

Not to worry. If you fail your smog and emissions test, with your approval we’ll investigate the source of the problem. Once we’ve accurately tested the vehicle and located the source of the issue, we’ll discuss the repairs needed to pass.

And about the test—the cost of the initial test covers a re-test if necessary. So, if your vehicle fails the emission test, we’ll work with you to get everything in working order. Then we’ll retest so you can renew your license plates and get back on the road.

The Telle Difference

When it’s time for an emissions test, you should take your car to Telle Tire & Auto Centers. Since 1942, St. Louis car owners have trusted Telle to provide the highest level of service and value.

And, while people might come to us for our great value, they return because of the security of our warranty. Telle’s National Warranty Program covers both parts and labor for a full three years or 30,000 miles. Why do we go the extra mile to offer a better warranty? Because we don’t want you to worry about your car. After all, that’s our job.

Trust your car with the automotive repair technicians that go the extra mile.

Let’s Talk About Your Car