Finding an Approved Testing Station Near You

Colorado emissions tests happen at stations licensed by the Colorado Department of Public Health and Environment (CDPHE). You cannot test at a random mechanic shop — the station must hold an active Emissions Testing Program (ETP) license. The state publishes a searchable list of licensed stations on the CDPHE website, organized by county, so you can find one within a few miles of your home or work.

Most testing stations are independent repair shops, tire shops, or quick-lube facilities that added emissions testing as a service. A few dealerships also perform testing. The test itself takes about 10 to 15 minutes and costs between $20 and $40, depending on the station — the state does not set a fixed price. You do not need an appointment at most locations, though calling ahead during busy seasons (late summer and fall) can save you a wait.

Your vehicle must be registered in Colorado to test at a Colorado station. If you recently moved to the state or bought a vehicle out of state, you will need to register it first before you can schedule a test. The registration address on your vehicle's title or registration card is what matters — not where you currently live.

Key Takeaways

  • Only stations with an active CDPHE Emissions Testing Program license can perform the test, and the state maintains a searchable county-by-county list on its website.
  • Testing costs between $20 and $40 per vehicle and takes 10 to 15 minutes, with no appointment required at most locations.
  • Your vehicle must be registered in Colorado before you can test, regardless of where you currently live.
  • If your vehicle fails, you have 60 days to repair it and retest at any licensed station without paying the testing fee again.
  • Diesel vehicles, motorcycles, and vehicles older than 1975 are exempt from Colorado emissions testing.

How to Search the State's Station Directory

The CDPHE maintains the official list of licensed testing stations at the Air Quality Control Commission website. You can search by county or by city name. Each listing includes the station's address, phone number, and hours of operation. Some stations are open weekdays only; others stay open on Saturdays. A few operate on Sunday mornings, though these are less common.

When you call a station to confirm they are still testing, ask whether they accept walk-ins or prefer appointments. Ask also whether they test your vehicle's model year — a few older stations may not have updated equipment for the newest model years, though this is rare. Some stations also offer other services like oil changes or tire rotations, so you can combine your emissions test with routine maintenance if you want.

What to Bring to Your Test

Bring your vehicle's registration card or proof of Colorado registration. The station will need to verify that your vehicle is registered in the state and that the test is due. You will also need a valid photo ID. Some stations accept payment by card; others take cash only. Call ahead if you are unsure.

Your vehicle should be in normal operating condition — the engine should start easily and run without obvious problems. If your check-engine light is on, the test will likely fail, and you will need to have the vehicle diagnosed and repaired before retesting. If your vehicle has been sitting unused for more than a month, drive it for at least 15 minutes before testing to warm up the engine and clear any temporary fault codes.

What Happens If Your Vehicle Fails

If your vehicle fails the emissions test, the station will give you a printed report showing which emissions standard it did not meet. You then have 60 days to repair the vehicle and retest. The second test is free — you only pay the testing fee once per test cycle, not once per attempt. You can retest at any licensed station, not necessarily the one where you failed.

Common reasons for failure include a faulty oxygen sensor, a loose or missing gas cap, a failing catalytic converter, or a malfunctioning fuel injector. A mechanic can read your vehicle's diagnostic codes to pinpoint the problem. If repairs cost more than a certain threshold (the amount varies by vehicle age and model year), Colorado offers a Repair information Program that may help cover costs. Contact the CDPHE directly to learn whether your vehicle qualifies.

If you repair the vehicle and pass the retest within 60 days, your emissions compliance is current. If you do not retest within 60 days, your registration will be suspended, and you cannot legally drive the vehicle until you pass a test and renew your registration.

Vehicles Exempt from Colorado Emissions Testing

Not every vehicle on Colorado roads needs an emissions test. Diesel-powered vehicles are exempt, as are motorcycles and any vehicle manufactured before 1975. Vehicles registered as classic cars or antiques may also be exempt, depending on how often you drive them — check your registration documents or call your county clerk's office to confirm.

Electric vehicles do not require emissions testing because they produce no tailpipe emissions. Hybrid vehicles do require testing, since they still have a gasoline engine that produces emissions part of the time.

Testing Requirements by County

Emissions testing is required in Colorado's Front Range counties — Denver, Boulder, Broomfield, Jefferson, Adams, Arapahoe, Douglas, and El Paso — plus a few areas around Fort Collins and Pueblo. If your vehicle is registered in one of these counties, you must test every two years as part of your registration renewal. If you live in a county outside these areas, your vehicle does not require an emissions test.

You can check whether your county requires testing by looking at your vehicle registration renewal notice. If testing is required, the notice will say so and will give you a important date. You must pass the test and submit proof to your county clerk before your registration expires.

Frequently Asked Questions

Can I test my vehicle in a different county than where it is registered?

No. You must test in the county where your vehicle is registered. If you moved to a different county, you need to update your vehicle registration with your new address first, then test in your new county.

What if I cannot find a testing station near me?

Call your county clerk's office or the CDPHE Air Quality Control Commission directly. They can tell you the nearest licensed station and may be able to help if a station has closed or stopped testing. In rare cases, the state can issue a temporary waiver if no station is available within a reasonable distance.

Do I need to make an appointment, or can I just show up?

Most stations accept walk-ins, but calling ahead is a good idea, especially during peak testing season (August through October). A few busy locations may require appointments on certain days. The station's phone number is on the CDPHE directory.

What if my vehicle fails and I cannot afford to repair it?

Colorado's Repair information Program may cover some or all of the repair costs if your vehicle fails and the repairs exceed a certain amount. Contact the CDPHE to find out whether your vehicle qualifies based on its age, value, and your household income.

How long does the actual test take?

The test itself takes 10 to 15 minutes. The station will plug a diagnostic device into your vehicle's onboard computer, run the test, and print your results. If you arrive during a busy time, you may wait 30 minutes or more before the test begins.