What Illinois requires for emissions testing

Illinois requires emissions testing for most vehicles registered in the state, but the rules depend on where you live and how old your car is. The state divides the requirement into two regions: the Chicago metropolitan area (Cook, DuPage, Kane, Lake, McHenry, and Will counties) and the rest of Illinois. Chicago-area vehicles must pass an emissions test every two years; vehicles outside that region must test every four years. Vehicles that are model year 1996 or newer are subject to testing; older vehicles are exempt.

You must have your emissions test completed before your vehicle registration expires. The test itself checks your vehicle's on-board diagnostic system and tailpipe emissions to may support they meet state standards. If your vehicle fails, you have options to repair it and retest, but you cannot legally drive with an expired registration while waiting for repairs.

Key Takeaways

  • Chicago-area vehicles (six counties) test every two years; all other Illinois vehicles test every four years.
  • Only vehicles model year 1996 and newer must test; older vehicles are automatically exempt.
  • You must complete testing before your registration expires, or you cannot legally drive the vehicle.
  • If your vehicle fails, you can repair it and retest at the same facility or a different one within 30 days.
  • The test costs between $20 and $30 depending on the testing station.

Where to get your vehicle tested in Illinois

Illinois uses a network of private testing stations rather than state-run facilities. You can find an approved emissions testing station through the Illinois Environmental Protection Agency (IEPA) website, which maintains a searchable list of stations by county. Most stations are repair shops, quick-lube facilities, or dedicated testing centers. You do not need an appointment at most locations, though some stations accept them and may have shorter wait times.

When you arrive at a testing station, bring your vehicle registration and proof of insurance. The technician will plug a diagnostic scanner into your vehicle's on-board diagnostic port (usually located under the steering wheel or dashboard) and run the test, which typically takes 10 to 15 minutes. You will receive your test results when ready, either as a pass or a fail with specific emissions readings.

What happens if your vehicle fails the emissions test

A failed emissions test does not mean your registration is automatically invalid, but you cannot renew your registration until you pass. You have 30 days from the test date to repair your vehicle and retest at any approved station. If you repair the vehicle yourself or at a shop, you can return to the same station or go to a different one for the retest.

If your vehicle fails a second time after repairs, you may be may be able to access for the Repair information Program, which provides a voucher worth up to $500 toward emissions-related repairs at a participating shop. To use this program, your vehicle must have failed twice in a row, and you must meet income requirements. Contact the IEPA directly or ask your testing station for details on how the process works for the voucher.

Emissions testing for new and used vehicle purchases

If you buy a used vehicle in Illinois, the seller is responsible for providing a passing emissions test before the sale is complete. The test must be dated within 30 days of the sale. When you register the vehicle in your name, you will need to show proof of that passing test. If the vehicle fails, the seller must either repair it and retest or disclose the failure to you in writing.

New vehicles (model year 2024 and newer) are exempt from emissions testing for their first two years of registration in Illinois. After that, they follow the standard testing schedule based on your county. If you move from another state to Illinois, your vehicle must pass an Illinois emissions test before you can register it here, even if it passed testing in your previous state.

Emissions testing important date and registration renewal

Your emissions test must be completed before your vehicle registration expires. The IEPA sends renewal notices 60 days before expiration, and you can renew your registration online, by mail, or in person at a Secretary of State facility. If you renew online or by mail, you will need to provide your emissions test results or a waiver number if your vehicle is exempt.

If your registration expires before you complete a passing emissions test, you cannot legally drive the vehicle on public roads. If you are stopped by police, you face a ticket for expired registration. If you know your test is coming up and you are close to your registration expiration date, schedule your test at least two weeks before the expiration date to allow time for repairs if needed.

Vehicles exempt from Illinois emissions testing

Several categories of vehicles do not need to pass an emissions test. All vehicles model year 1995 and older are permanently exempt. Diesel-powered vehicles are exempt unless they are model year 2007 or newer and registered in the Chicago area. Motorcycles and mopeds are exempt. Vehicles registered as classic cars or antique vehicles are also exempt, though you must register them under that classification.

If your vehicle qualifies for an exemption, you still need to register it with the Secretary of State, but you will not be required to submit emissions test results. When you renew your registration, you may be asked to confirm the exemption status. If you are unsure whether your vehicle qualifies, contact the IEPA or ask at your local Secretary of State office.

Frequently Asked Questions

Can I get an extension if I cannot complete my emissions test before my registration expires?

No, the state does not grant extensions for emissions testing. However, you can renew your registration online or by mail up to 30 days before expiration, which gives you time to schedule and complete your test. If your registration has already expired, you must complete the test and renew in person at a Secretary of State facility.

What if I just moved to Illinois from another state?

Your out-of-state registration is valid for 30 days after you move. You must register your vehicle in Illinois within that time and obtain a passing emissions test before the registration is finalized. If your vehicle fails, you have 30 days to repair and retest before your new Illinois registration expires.

Do I need emissions testing if I only drive my car occasionally?

Yes, if your vehicle is registered in Illinois and is model year 1996 or newer, it must pass emissions testing on the required schedule regardless of how often you drive it. The test is tied to your registration renewal date, not your mileage or usage.

What is the difference between a pass and a conditional pass on an emissions test?

Illinois uses a pass or fail system; there is no conditional pass. If your vehicle passes, your registration can be renewed. If it fails, you must repair it and retest within 30 days. Some stations may provide a detailed report showing how close your vehicle came to passing, which can help a mechanic target repairs.

Can I test my vehicle early to renew my registration before it expires?

Yes, you can test your vehicle up to 60 days before your registration expires. This is useful if you want to renew early or if you are concerned about potential repairs. The test results are valid for 30 days, so plan accordingly if you test very early.