Finding an emissions test station near you

Colorado requires emissions testing in the Denver metro area and a few surrounding counties. You can find stations through the state's official search tool at cdphe.colorado.gov — look for the "Find a Test Station" link under the Air Quality Control Commission section. The search returns stations by county and shows their hours and phone numbers.

You can also call your county air quality office directly. For Denver and Adams counties, that's the Metro Denver Air Quality Council at 303-433-8004. For El Paso County (Colorado Springs area), contact the Pikes Peak Area Council of Governments. Having your vehicle's VIN and current registration handy speeds up the process when you call.

Most stations are independent repair shops, not dealerships. They're scattered across the metro area — you don't have to go to a specific location. Any certified station in your county will test your vehicle and submit the results to the state.

Key Takeaways

  • Use the state's online search tool at cdphe.colorado.gov to find stations by county, or call your county air quality office for a list.
  • Emissions testing is required only in the Denver metro area and parts of El Paso and Weld counties, not statewide.
  • Any certified station in your county can perform the test; you do not have to use a specific location or dealership.
  • Most stations charge between $20 and $30 for the test and submit results electronically to the state within hours.

Which Colorado counties require emissions testing

The Denver metro area — Adams, Arapahoe, Boulder, Denver, Douglas, Jefferson, and Weld counties — requires all vehicles to pass an emissions test before registration renewal. El Paso County (Colorado Springs) also requires testing. If you live outside these counties, you do not need an emissions test.

If you live in a testing county but your vehicle is registered elsewhere, you still need to test it in Colorado before you can renew your registration here. The state's registration system flags vehicles that are due for testing and will not process renewal until the test is complete.

What to bring and what to expect at the test station

Bring your vehicle registration and a photo ID. The technician will plug a diagnostic scanner into your vehicle's onboard computer port (usually under the steering wheel) and run a quick test. The whole process takes 10 to 15 minutes. You do not need to turn off the engine or leave the vehicle — you stay in the waiting area while the test runs.

The station will print a receipt showing whether your vehicle passed or failed. If you pass, the results go to the state automatically, usually within a few hours. You can then renew your registration online or at the DMV. If you fail, the receipt will show which emissions system needs attention — typically the catalytic converter, oxygen sensors, or the fuel system.

What happens if your vehicle fails the test

A failed test means your vehicle's emissions are above the state limit for that model year. You have 60 days from the test date to get the vehicle repaired and retested at no charge. The repair shop does not have to be the same station that tested you — any certified station can do the retest.

If you repair the vehicle and pass the retest within 60 days, you can renew your registration. If you do not retest within 60 days, your registration will not renew until you do. Some repair shops offer a "test and repair" package where they diagnose the problem and fix it in one visit, then retest you on the spot.

Cost and timing for emissions testing

The test itself costs between $20 and $30 at most stations. Some stations charge slightly more or less depending on the vehicle type — diesel vehicles sometimes cost a few dollars more. Call ahead if cost is a concern; stations are required to post their prices.

Results are submitted electronically and show up in the state system within hours, sometimes the same day. You do not have to wait for a paper certificate — the state knows you passed as soon as the station uploads the data. You can renew your registration when ready online or at the DMV.

Testing your vehicle before the registration important date

You can test your vehicle anytime during the year, not just when your registration is about to expire. Many people test early to avoid the rush in the weeks before their registration renewal date. The test results are valid for one year from the test date.

If your registration expires in June, you can test in May, April, or even earlier. The state will accept the test result whenever you renew, as long as the test is not older than one year. Testing early also gives you time to repair and retest if you fail, without scrambling to meet a important date.

Frequently Asked Questions

Can I test my vehicle at any station in Colorado, or does it have to be in my county?

It has to be in your county. If you live in Denver, you test at a Denver station. If you move to a different testing county, you test at a station in your new county. Stations in non-testing counties are not certified to perform the state test.

What if I just bought a used car and do not know if it will pass?

You can test it before you complete the purchase or transfer the title. Some stations will test a vehicle even if the registration is in someone else's name. Call the station first and ask — they may ask you to bring the seller's registration or a bill of sale. If it fails, you know before you own it.

Do I have to test my vehicle every year?

Yes, every year when you renew your registration in a testing county. The test results are valid for one year only. You can test anytime during that year, but you must have a passing test on file before the state will renew your registration.

What if I cannot get to a test station during their hours?

Most stations are open weekdays and some weekend hours. Call ahead to find a station with hours that work for you. If you cannot test before your registration expires, you can renew your registration online or by mail and test within 30 days after expiration — but your vehicle cannot be driven legally until the test is complete and uploaded to the state.

Can I test a vehicle that is not registered yet?

No. The vehicle must have a current registration in Colorado before you can test it. If you just bought a car, transfer the title and register it first, then schedule the test. Some stations will let you test with a temporary registration or bill of sale, but it varies — call ahead to ask.