Emissions Testing in Illinois

Testing Requirements

Current Testing Requirements in Illinois

Illinois operates the Vehicle Emissions Testing Program under the Illinois Vehicle Emissions Inspection Law of 2005. The Illinois EPA administers the program, and the Illinois Air Team manages day-to-day testing operations at centralized inspection sites throughout the Chicago metro area and Metro-East St. Louis region. The program exists because these areas do not meet the National Ambient Air Quality Standards for ozone under the federal Clean Air Act. For model year 1996 and newer light-duty vehicles, an OBD-II diagnostic test is performed. Heavy-duty vehicles from model year 2007 and newer with a GVWR between 8,501 and 14,000 pounds also receive the OBD-II test. Self-service kiosks and mobile testing units are being introduced as additional testing options.

Who Needs an Emissions Test

Most gasoline-powered passenger cars, trucks, vans, and SUVs model year 1996 and newer that are four or more model years old and registered in a designated testing area must pass an emissions test. Heavy-duty vehicles from 2007 and newer with a GVWR between 8,501 and 14,000 pounds are also required to test. Dealers must provide a valid emissions certificate when selling a used vehicle in a testing area. New residents have 30 days to register their vehicle and will receive a test notice in the mail. Diesel-powered vehicles, motorcycles, antique vehicles, farm vehicles, and vehicles with a GVWR over 14,000 pounds are exempt. Vehicles model year 1995 and older are also exempt. Electric vehicles are not subject to testing.

How Often Tests Are Required

Emissions testing is required every two years on a model year odd/even cycle. Vehicles with even-numbered model years are tested in even-numbered calendar years, and vehicles with odd-numbered model years are tested in odd-numbered calendar years. A vehicle first becomes eligible for testing when it is four model years old. The Illinois Secretary of State's office sends a test notice when a vehicle's registration renewal requires an emissions inspection. Testing should be completed several weeks before the registration expires to allow time for any needed repairs.

Where Emissions Testing Is Required

Testing is required in Cook, DuPage, and Lake counties in full. Parts of Kane, Kendall, McHenry, and Will counties in the Chicago area are also covered, determined by specific zip codes. In the Metro-East St. Louis region, parts of Madison, Monroe, and St. Clair counties are covered, also determined by zip codes. Vehicles registered outside these areas do not require testing. The Illinois Air Team website has a Vehicle Eligibility Check tool where drivers can enter their license plate or VIN to confirm whether their vehicle requires a test.

What Happens During the Test

For model year 1996 and newer light-duty vehicles, a technician connects an OBD-II scanner to the vehicle's diagnostic link connector and checks for stored diagnostic trouble codes, readiness monitor status, and the malfunction indicator lamp. A lit check engine light results in failure. A damaged or inaccessible diagnostic link connector also results in failure. Any device plugged into the OBD data link connector, such as an insurance dongle, GPS tracker, or scan tool, must be removed before testing. The test typically takes 15 to 40 minutes depending on the vehicle and station wait times.

Areas in Illinois That Require Emissions Testing

Within the Chicago area, cities where testing is required include Chicago, Aurora, Naperville, Joliet, Elgin, Waukegan, Evanston, Schaumburg, Arlington Heights, Cicero, Oak Park, Berwyn, Skokie, Des Plaines, Palatine, Wheaton, Downers Grove, Orland Park, and Bolingbrook. In the Metro-East St. Louis region, cities include East St. Louis, Belleville, Collinsville, O'Fallon, Granite City, Edwardsville, and Alton. Cities outside the testing areas, such as Springfield, Peoria, Rockford, Champaign, Bloomington, and Decatur, do not require emissions testing. Testing boundaries within partially covered counties are determined by zip code, so drivers near the edges of the program area should verify their status.

How the Emissions Test Works in Illinois

Drivers take their vehicle to an Illinois Air Team testing site. No appointment is needed. The test fee is approximately $20. Stations accept various payment methods. Bring your vehicle registration or renewal notice. When you arrive, a technician performs the OBD-II scan and provides results at the end of the test. If the vehicle passes, the results are transmitted electronically to the Secretary of State's office and registration can be renewed. The Illinois Air Team website lists all station locations and current wait times. If the vehicle fails, the owner receives a Vehicle Inspection Report with detailed failure reasons and a list of repair facilities within 15 miles. Repairs should be performed by a Recognized Repair Technician. If the vehicle fails a second time and the owner has spent at least $1,176 (as of 2026, adjusted annually) on qualifying emissions-related repairs at a Recognized Repair Technician facility, a repair waiver may be available. An economic hardship extension may also be available for owners who meet income requirements and have spent at least $588 on emissions repairs. Registration renewal will be denied without a passing test or an approved waiver. Fines for failing to test can reach $300.