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In Illinois all eligible vehicles must go through emissions inspection every 2 years. This “smog” check includes a test of your car’s emissions to determine whether smog emissions are within tolerance.
Illinois laws require emissions testing for gasoline powered passenger vehicles, trucks and buses older than 4 years, but not older than 1996. Emissions testing (smog testing) is done in the following Illinois counties: Cook, Dupage, and Lake, and certain ZIP codes in Kane, Kendall, McHenry, Will, Madison, Monroe, and St. Clair counties.
The following article will give you the basics of smog laws in Illinois. Below you can find out how smog checks are performed in the state of Illinois, and which vehicles can be exempt from the laws. This article is based on latest Illinois regulations in effect since November 2016.
Emissions testing in Illinois is only required in the following counties:
Only certain zip codes in the following counties require smog testing. Vehicles within zip codes specified below are excluded from Illinois emissions testing laws:
Your vehicle requires emissions test in Illinois if:
New Illinois residents must first register their vehicle before conducting emissions test. Your test notice will specify when you must do your smog check.
Valid emissions test is required for completing vehicle registration, renewal, or reinstating a suspended registration. Emissions test is valid for 2 years, after which your vehicle must be retested.
When purchasing a vehicle from a private owner, it is the buyer’s responsibility to get a valid emissions test. When purchasing vehicles from used car dealers, the dealer must issue a valid emissions test.
Diesel-powered vehicles or those newer than 4 years are exempt from smog check. Motorcycles are also not undergoing emissions testing. Further exempt vehicles include:
Vehicles with out of state registration are also exempt from Illinois smog check.
For most 1996 and newer passenger cars and light duty trucks, vans and sport utility vehicles, and 2007 and newer heavy duty vehicles with gross weight rating between 8,501 and 14,000 pounds, an On-Board Diagnostics (OBD) test is used.
OBD testing consists of connecting a scanning tool to your vehicle’s on-board computer to determine if there are any issues with your vehicle.
Assuming your vehicle was originally manufactured with them, the following emissions control devices may be tested during emissions testing:
To find your nearest emissions inspection station see this webpage: http://www.epa.state.il.us/air/vim/locations.html.
Failing emissions testing means your vehicle will have to be repaired and re-tested before you can pass the smog inspection. It is recommended to choose a Recognized Repair Technician.
Upon failing a smog check your will receive the following documents:
Based on these documents your emissions inspector or repair technician will help you determine how to repair your vehicle, assuming it is required.
If your vehicle does not meet emissions or smog standards set by Illinois emissions test laws, you can apply for a waiver or have your vehicle repaired. Waivers are issued if:
Emissions testing requires a $20 fee. Some counties may not charge a fee.
When you pass safety and emissions inspection, don’t forget to keep your receipt. This will serve as proof of your completed inspection and you may require it at a later date.
Please note we only provide this information about vehicle emissions for informational purposes. You should always double-check current official Illinois laws and regulations to ensure this information is correct.
This article about Illinois Emissions Inspection & Smog Laws was last updated in 2024. If any of our information is incomplete or outdated please let us know. Thank you!
