Did you know that it is actually not too uncommon for your vehicle to fail the Illinois emissions test? Sometimes our vehicles develop issues that we just don’t notice, and in some cases, those issues develop the same day you plan on getting your test done. We have created a guide below to explain to drivers in the Edwardsville, IL area tips for their emissions test.
The Basics of an Emissions Test

In Illinois, the law states that you must test your vehicle every two years starting 4 years from the day that it was sold. There are some exceptions for those that are living in certain zip codes. Nearly all emissions tests are due right before or on the day of your registration renewal. If your vehicle does not pass the emissions test, then you cannot get your vehicle’s registration for the current year. Hopefully, you won’t wait till the last minute. By having your test done a couple of weeks before, you will still have time to repair your vehicle if it does not pass the test.
Common Reasons for Failing the Test
Failing an emissions test can be caused by a number of issues with your vehicle. However, there are a couple of common codes that most people experience including:
- Faulty Evaporative Emissions Control System
Don’t let the name of this system scare you. This system refers to the vapors in the fuel system and tank. These are trapped and are partially reused so that the vapors do not get released out into the air.
- Fuel Metering
This issue stems from a variety of problems, including an ECU that is not properly metering out the fuel. It can also be an issue such as a bad fuel Injector
- Failed Air Injection System
Fresh air from the outside is forced into the exhaust in order to help it dilute the gases. If this system fails, the exhaust gas levels of hydrocarbons and carbon monoxide become too high.
- Failing Oxygen Sensors
These sensors monitor the oxygen levels in your vehicle’s exhaust gas. As time goes on, these sensors can become clogged or stop working altogether. It is best to get these sensors replaced if you notice something wrong with your emissions results.
Professional Tips for Passing Your Emissions Test

Here are some tips that our team at Rob’s Discount Mufflers have found to help you pass your emissions test. Make sure to:
- Change your air filter.
- Change the oil, especially if its dirty.
- Put premium gas in your vehicle.
- Properly inflate your tires.
- Be sure to drive for at least 15-20 minutes before the test.
- Remove any junk that is in your trunk or rear hatch.
If you are curious to learn more tips, give our team at Rob’s Discount Mufflers a call today!