How to locate a CO emissions test station near you
Colorado emissions testing happens at stations licensed by the state, not at random repair shops or gas stations. Your state's Department of Revenue, Division of Motor Vehicles (DMV) maintains a searchable list of all active test-only facilities and repair shops that perform emissions work. You can search by county or city on the DMV website to find stations within a reasonable drive.
Test-only stations run the emissions equipment but do not repair vehicles. Repair shops that perform emissions testing can both test and fix problems on-site, which can save you a trip if your vehicle fails. Both types are equally valid for meeting Colorado's testing requirement — the difference is whether you need repairs afterward.
The DMV list updates regularly as stations open and close, so searching online before you go is more reliable than using an old list or calling ahead. Most stations accept walk-ins, but calling first to confirm hours and current wait times can save you a wasted trip, especially during peak testing periods in the fall and spring.
Key Takeaways
- Colorado's DMV website has a searchable database of all licensed emissions testing stations, organized by county and city.
- Test-only stations perform the emissions test but cannot repair your vehicle, while repair shops can do both testing and repairs in one visit.
- Stations accept walk-ins in most cases, but calling ahead to check hours and wait times can help you plan your visit.
- You will need your vehicle registration and proof of insurance when you arrive for testing.
What to bring to your emissions test appointment
Bring your vehicle registration and proof of current insurance. Colorado requires both documents to be presented at the test station before the technician will run your vehicle through the emissions equipment. If you cannot locate your registration, contact your local county assessor's office or the DMV to request a replacement before your test.
Your vehicle's odometer reading will be recorded during the test, so make sure the odometer is working and visible. If your odometer is broken, the test station will note this on your results, and you may need to repair it before your vehicle can pass inspection in future years.
Arrive with a vehicle that has been driven for at least 20 minutes so the engine is warm. A cold engine can produce inaccurate emissions readings and cause a failed test even if your vehicle would pass when fully warmed up. If you drive directly from home to the test station, plan for a short warm-up period before entering the testing bay.
Understanding test results and what happens if you fail
Your test results are printed when ready after the test completes. A passing result means your vehicle meets Colorado's emissions standards for that year and you can register your vehicle. A failing result lists which emissions standards your vehicle did not meet — typically nitrogen oxides (NOx), particulate matter, or hydrocarbon levels.
If you fail, you have options depending on your vehicle's age and the severity of the failure. Vehicles 1996 and newer that fail can be taken to a repair shop for diagnosis and repair, then retested at no additional fee within 30 days. Older vehicles and vehicles that fail by a large margin may have different rules, so ask the test station for guidance on your specific situation.
Some repair shops offer a "free retest" after repairs, meaning they cover the cost of the second test if they performed the repair work. This is not required by law but is common practice. If you choose a different repair shop than the one that tested your vehicle, you will pay the standard test fee again.
Cost of emissions testing in Colorado
Test fees vary by station but typically range from $20 to $35 for a standard emissions test. Some stations charge slightly more for diesel vehicles or for retests. Call ahead or check the station's website to confirm the exact fee, as prices can differ between test-only facilities and repair shops.
If your vehicle fails and you need repairs, the repair cost depends entirely on what is wrong with your vehicle. Common repairs include replacing an oxygen sensor, fixing a faulty catalytic converter, or addressing engine control issues. Repair costs can range from under $100 for a sensor replacement to $500 or more for major components.
Some repair shops offer a "warranty" on emissions repairs, meaning they will retest your vehicle for free if it fails again within a set period. Ask about this when you call for a repair estimate, as it can protect you if the first repair does not solve the problem.
When your vehicle is due for emissions testing
Colorado requires emissions testing every two years for most vehicles. Your test is due in the same month as your vehicle registration expires. You can take your test up to 60 days before your registration expires, so you have a two-month window to get tested without being late.
If you miss the important date and your registration expires, you cannot legally drive your vehicle until you pass an emissions test and renew your registration. Driving an unregistered vehicle can result in a traffic citation and fines. If you realize you are past due, take your vehicle to a test station when ready and then renew your registration online or at your county assessor's office.
New vehicles are exempt from emissions testing for their first four model years. After that, they enter the regular two-year testing cycle. If you buy a used vehicle, check with the seller or your county assessor to find out when the previous owner's test was completed so you know when your first test is due.
Emissions testing in different Colorado counties and regions
Denver, Boulder, and the northern Front Range have stricter emissions standards than the rest of Colorado because of air quality concerns in those areas. If you live in or near Denver, your vehicle must meet the Front Range Air Quality Control Region standards, which are more stringent than standards in other parts of the state. Test stations in these areas are equipped to run the appropriate test for your location.
Rural counties and areas outside the Front Range have fewer test stations available, so you may need to drive farther to reach one. The DMV database shows all stations statewide, so you can plan ahead if you live in a remote area. Some counties have only one or two active stations, so calling ahead to confirm hours is especially important.
If you move to a different county or region during the year, your next emissions test will follow the standards of your new location. You do not need to retest when ready after moving — your current registration remains valid until it expires, and your next test will be due in the new county according to your registration expiration date.
Frequently Asked Questions
Can I get my emissions test done at any repair shop?
No. Only stations licensed by Colorado's DMV can perform official emissions tests. You can find licensed stations on the DMV website. Some licensed repair shops perform testing, but not all repair shops are authorized to do so.
What if I fail my emissions test and cannot afford repairs right away?
You cannot register your vehicle until it passes an emissions test. If repairs are expensive, get a second opinion from another repair shop or ask about payment plans. Some shops offer financing for emissions repairs, though this varies by location.
Do I need to make an appointment or can I just show up?
Most stations accept walk-ins, but wait times vary by location and time of year. Calling ahead to ask about current wait times helps you plan your visit. Some busy stations may suggest coming back at a slower time if the wait is very long.
What happens if my vehicle fails the emissions test twice?
After two failed tests within a 12-month period, your vehicle may be subject to additional requirements or restrictions. Contact your county assessor's office or the DMV for guidance on your specific situation, as rules vary based on vehicle age and failure severity.
Can I test my vehicle in a different county than where I live?
Yes. You can test your vehicle at any licensed station in Colorado, regardless of which county you live in. However, the test will follow the emissions standards for the county where the station is located, so if you test in a stricter county, your vehicle must meet those higher standards.