What Aurora requires for emissions testing

Aurora, Colorado requires emissions testing as part of vehicle registration renewal for most gasoline-powered vehicles. The test measures tailpipe emissions — carbon monoxide, nitrogen oxides, and hydrocarbons — to may support your vehicle meets state air quality standards. You cannot renew your registration without a passing test result, and the test must be completed within a certain window before your registration expires.

The City of Aurora does not operate its own testing facility. Instead, you take your vehicle to any Colorado Department of Transportation (CDOT) approved testing station in the Aurora area or nearby. These are private businesses licensed by the state to perform the test. The test itself takes about 10 to 15 minutes and costs between $20 and $30, depending on the station.

Your vehicle is subject to testing if it is registered in Colorado and is a 1975 or newer gasoline vehicle. Diesel vehicles, motorcycles, and vehicles registered outside Colorado are generally exempt. If your vehicle fails, you have the option to repair it and retest, usually at a reduced fee.

Key Takeaways

  • Aurora requires emissions testing for most gasoline vehicles as part of registration renewal, and you must pass before your registration expires.
  • You choose any CDOT-approved testing station in Aurora or the surrounding area — the city does not run the test itself.
  • The test costs $20 to $30 and takes 10 to 15 minutes; you receive a pass or fail result when ready.
  • If your vehicle fails, you can repair it and retest at most stations for a lower fee, usually $10 to $15.
  • Diesel vehicles, motorcycles, and vehicles registered outside Colorado are exempt from testing.

Finding a testing station in Aurora

CDOT maintains a searchable list of approved testing stations on its website. You can filter by location and find stations in Aurora and the when ready surrounding area. Most stations are independent repair shops, tire shops, or dedicated emissions testing facilities. Call ahead to confirm hours and whether they have same-day appointments available, as wait times vary by season.

Many stations in the Aurora area are concentrated along East Colfax Avenue, South Parker Road, and near the I-25 corridor. If you cannot find a convenient Aurora location, you can test at any approved station in the Denver metro area — your registration address does not restrict where you can test.

Timing and registration renewal

You must complete emissions testing within 90 days before your registration expires. For example, if your registration expires on June 30, you can test anytime after April 1. Testing too early means your result may expire before you renew, and you would need to test again.

Once you pass, the testing station provides you with a certificate or electronic proof of passing. You bring this to the Colorado Division of Motor Vehicles (DMV) when you renew your registration, or you can renew online if the station has reported the result electronically. Most modern stations report results directly to the state within 24 hours.

What happens if your vehicle fails

A failure means your vehicle's emissions exceed Colorado standards. You will receive a detailed report showing which pollutants were out of range. Common causes include a faulty oxygen sensor, a loose gas cap, a failing catalytic converter, or engine timing problems.

You have two paths: repair the vehicle and retest, or request a waiver. Most stations offer retest discounts of $10 to $15 if you return within 30 days. If repairs cost more than a certain threshold — currently $375 in Colorado — you may be may be able to access for a repair cost waiver, which allows you to register without passing. To request a waiver, you typically need a written repair estimate from a mechanic showing the cost exceeds the threshold. Contact the testing station or CDOT for the current waiver process.

Vehicles that do not require testing

Diesel vehicles are exempt from emissions testing in Colorado, even if registered in Aurora. Motorcycles, mopeds, and vehicles registered in other states are also exempt. Vehicles model year 1974 and older are exempt. New vehicles — typically those less than four model years old — may be exempt during their first registration period, though this varies by year.

If you are unsure whether your vehicle is subject to testing, the CDOT website includes an exemption checker, or you can call your local DMV office. Attempting to register a vehicle that requires testing without a passing result will result in registration denial.

Online renewal and electronic reporting

Colorado allows online registration renewal through the DMV website. If your testing station reports results electronically — which most do — your pass result appears in the state system within 24 hours. You can then renew online without visiting an office or bringing a physical certificate.

If your station does not report electronically, you will receive a paper certificate at the time of testing. You must bring this to a DMV office or include a photo of it with your online renewal process. Keep the certificate until your registration is confirmed renewed.

Cost breakdown and payment

The test itself costs $20 to $30 at most Aurora-area stations. If you fail and retest within 30 days, the retest fee is usually $10 to $15. If you fail and wait more than 30 days before retesting, you may pay the full test fee again. Some stations charge a small additional fee for electronic reporting or for printing a physical certificate.

Payment is typically cash or card at the station. No online payment is required for the test itself, though you will pay registration renewal fees to the state when you renew — that is separate from the emissions test cost.

Frequently Asked Questions

Can I test my vehicle before my registration expires?

Yes, but only within 90 days before expiration. Testing earlier than that means your result may expire before you renew. Check your registration expiration date and count back 90 days to find the earliest test date.

What if I move out of Aurora after testing but before renewing?

Your test result is valid statewide. You can renew your registration at any Colorado DMV office or online, regardless of where you tested or where you now live. The result follows your vehicle, not your location.

Do I need an appointment, or can I just walk in?

Most stations accept walk-ins, but appointment availability varies by location and season. Calling ahead ensures shorter wait times, especially during peak renewal periods in spring and fall.

What if the testing station says my vehicle cannot be tested?

Some vehicles have mechanical issues that prevent safe testing — for example, a check engine light that indicates a serious problem. The station will advise you to repair the vehicle first. You can take it elsewhere for a second opinion, or address the underlying issue and return to the same station.

Can I test in a different county and still register in Aurora?

Yes. Your test result is valid anywhere in Colorado. You can test in Denver, Littleton, or any other approved station and still renew your Aurora registration online or at any DMV office.