Finding an Approved Emissions Testing Center
Colorado requires emissions testing for most vehicles in the Denver metro area and some surrounding counties. You'll need to find a Colorado Department of Revenue-approved testing center to get your vehicle tested. These centers are private businesses — gas stations, repair shops, and dedicated testing facilities — that have been certified to run the state's emissions equipment.
The official list of approved centers is maintained by the Colorado Department of Revenue's Division of Motor Vehicles. You can search for centers by county and city on their website, which shows the business name, address, phone number, and hours. Not every repair shop or gas station offers emissions testing, so using the official list saves you a trip to a place that doesn't have the equipment.
Testing centers in your area may have different hours and wait times. Some are open evenings and weekends; others operate only during business hours. Calling ahead to ask about current wait times and whether you need an appointment can save you time, especially during peak testing months in the spring and fall.
Key Takeaways
- Only Colorado Department of Revenue-approved centers can perform emissions tests, and you can find the official list on the DMV website filtered by your county.
- Testing centers are private businesses — repair shops, gas stations, and dedicated facilities — not government offices.
- You'll need your vehicle's registration and proof of insurance, and the test typically takes 15 to 30 minutes.
- Test results are sent directly to the state, and you'll receive a receipt showing whether your vehicle passed or failed.
- If your vehicle fails, you have 60 days to repair it and retest at any approved center without paying the testing fee again.
What to Bring and How the Test Works
Bring your vehicle registration and proof of insurance to the testing center. The technician will connect your vehicle to a diagnostic machine that reads your emissions system and measures tailpipe emissions. The test itself takes about 15 to 30 minutes, depending on the center's equipment and how busy they are.
During the test, the technician checks your vehicle's onboard diagnostic system and runs a tailpipe test. Your vehicle must be in good running condition — if the check engine light is on, the test will likely fail. Some centers will do a quick visual inspection of your emissions equipment before testing to catch obvious problems.
The test results are transmitted electronically to the Colorado Department of Revenue. You'll receive a printed receipt at the center showing whether your vehicle passed or failed. If you pass, your emissions compliance is recorded with the state, and you can renew your registration. If you fail, the receipt will show which emissions standards your vehicle did not meet.
Cost and Payment Methods
Colorado does not set a statewide price for emissions testing. Each approved center sets its own fee, which typically ranges from $15 to $30 for a standard test. Some centers charge more for additional services like diagnostic work or repairs. Call ahead or check the center's website to confirm the price before you go.
Most testing centers accept cash, debit cards, and credit cards. A few may accept only cash, so it's worth asking when you call. If you fail the test and need to retest after repairs, you will not pay the testing fee again — retests are free within 60 days of the original failure.
What Happens If Your Vehicle Fails
If your vehicle fails the emissions test, you have 60 days to repair it and return to any approved testing center for a retest. The retest is free, and you do not need to return to the same center where you failed. You'll need to bring your original failure receipt to the new center so they can link the retest to your original test.
Common reasons for failure include a faulty oxygen sensor, a malfunctioning catalytic converter, or a check engine light that indicates an emissions-related problem. A repair shop can diagnose the specific issue using the failure report from your test. Some testing centers also offer repair services, though you're not required to use them.
If you cannot complete repairs within 60 days, you can request a waiver from the Colorado Department of Revenue. Waivers are not automatic and require documentation that you've made a good-faith effort to repair your vehicle. Contact your local DMV office or the Division of Motor Vehicles for waiver information.
Testing Requirements by County and Vehicle Type
Emissions testing is required in the Denver metro area (Denver, Adams, Arapahoe, Boulder, Douglas, El Paso, Jefferson, Larimer, and Weld counties) and in some surrounding areas. If you live outside these counties, your vehicle may not need emissions testing, though you should check your county's specific rules when you renew your registration.
Most gasoline-powered vehicles registered in testing counties must be tested every two years. Diesel vehicles, motorcycles, and vehicles older than a certain model year may be exempt. New vehicles are typically exempt for the first few years of registration. Your registration notice will tell you whether your vehicle needs testing.
If you move to Colorado from another state, your vehicle will need to pass an emissions test before you can register it in a testing county. This is called an initial inspection and must be done at an approved center before you can complete your registration with the DMV.
How to Find the Right Center for Your Situation
If you need testing done quickly, look for centers with extended hours or weekend availability. Some dedicated emissions testing facilities have shorter wait times than repair shops that also do testing. If you failed a previous test and need a retest, any approved center will do — you don't need to return to the original location.
If your vehicle failed and you need repairs, you can use the testing center's repair services or take your vehicle to a separate repair shop. The testing center will provide a detailed failure report that any mechanic can use to diagnose the problem. Some people prefer to use their regular mechanic rather than the testing center's repair department.
If you're unsure whether your vehicle needs testing, check your registration renewal notice or call your county's DMV office. They can tell you whether your vehicle is subject to testing and point you toward approved centers in your area.
Frequently Asked Questions
Can I test my vehicle at any approved center, or do I have to go to a specific one?
You can go to any Colorado Department of Revenue-approved center. If you fail and need to retest, you can use a different center than the one where you failed. Just bring your original failure receipt so the new center can link the retest to your first test.
What if I just moved to Colorado and my vehicle has never been tested here?
You'll need an initial emissions test before you can register your vehicle in a testing county. Schedule a test at any approved center and bring your out-of-state registration and proof of insurance. Once you pass, you can complete your Colorado registration with the DMV.
Do I need an appointment, or can I just walk in?
It depends on the center. Some accept walk-ins and test vehicles on a first-come, first-served basis; others require appointments. Call ahead to ask about their process and current wait times. During peak months (spring and fall), wait times can be longer.
What if my check engine light is on?
Your vehicle will likely fail the emissions test if the check engine light is on, because the light indicates an emissions-related problem. Have the issue diagnosed and repaired before testing. Some repair shops can read the diagnostic code for a small fee to tell you what needs to be fixed.
How long does the test take, and can I wait while it's being done?
The test usually takes 15 to 30 minutes. Most centers allow you to wait in a waiting area while your vehicle is tested. Some may ask you to leave your keys and return later, especially if they're busy. Ask the center what to expect when you call.