What Aurora requires and when you need to test

Aurora requires emissions testing for most vehicles registered in the city, but the rules depend on your vehicle's age and type. Gasoline-powered cars, SUVs, and light trucks registered in Aurora must pass an emissions test every two years as part of the vehicle registration renewal process. Diesel vehicles, motorcycles, and vehicles older than 1975 are exempt from testing.

You do not need to test before your registration expires — you can test anytime during the two-year cycle, but the test results must be current when you renew. If your registration expires on June 15, you can test as early as June 15 of the previous year and still be valid at renewal time. Testing costs between $20 and $30 per vehicle at most testing stations in the Aurora area.

Key Takeaways

  • Aurora requires emissions testing every two years for gasoline vehicles, but you can test anytime during that cycle — not just before renewal.
  • You will need your vehicle's VIN, current registration, and proof of insurance to complete a test at any Colorado Department of Revenue-certified station.
  • If your vehicle fails, you have until your registration expires to repair it and retest at no additional charge.
  • Testing stations in Aurora are operated by private businesses, not the city, and hours vary by location — call ahead or check online before you go.
  • You cannot register your vehicle online or by mail if it requires testing and has not passed; you must complete the test first.

Where to find a testing station in Aurora

Aurora does not operate its own testing stations. Instead, the Colorado Department of Revenue certifies private businesses to perform emissions testing, and several operate within Aurora city limits. You can search for stations by location on the Colorado Department of Revenue website under "Emissions Testing Stations" — the search tool lets you filter by city and shows hours, phone numbers, and whether stations accept walk-ins or require appointments.

Common testing station chains in the Aurora area include Firestone, Midas, and independent shops certified by the state. Call ahead before visiting, because some stations book appointments weeks in advance during peak renewal periods (typically March through May and September through November), while others accept walk-ins with short waits. A few stations offer evening or weekend hours, but most operate during standard business hours only.

What to bring and what happens during the test

Bring your vehicle's current registration, proof of insurance, and your driver's license. The technician will record your vehicle identification number (VIN), mileage, and license plate, then connect a diagnostic machine to your vehicle's onboard computer port (located under the dashboard on the driver's side in most vehicles). The test itself takes 10 to 15 minutes and measures emissions from your tailpipe and fuel system.

You will receive a printed receipt showing whether your vehicle passed or failed. A passing result is valid for two years from the test date. If your vehicle fails, the receipt will list which emissions standards were not met — typically nitrogen oxides, particulate matter, or hydrocarbons. You do not pay for a retest if you fail; you can return to any certified station and test again at no charge once you have made repairs.

What to do if your vehicle fails the test

A failed test does not prevent you from driving your vehicle, but you cannot renew your registration until you pass. You have until your registration expiration date to repair the vehicle and retest. Common reasons for failure include a faulty oxygen sensor, a loose gas cap, a malfunctioning catalytic converter, or an engine running too rich (burning too much fuel).

If repairs are expensive, you may be may be able to access for the Colorado Vehicle Emissions Repair information Program, which can help pay for certain repairs on vehicles that fail testing. The program has income limits and covers repairs up to a set amount. Contact the Colorado Department of Public Health and Environment for current details on income thresholds and covered repairs, as the program's funding and rules change year to year.

How to renew your registration after passing

Once you have a passing test result, you can renew your registration online through the Colorado Department of Revenue website, by mail, or in person at an Aurora city office. Online renewal is fastest — you will need your registration renewal notice, driver's license number, and the test result number from your emissions receipt. The renewal notice arrives in the mail about 60 days before your registration expires.

If you renew online or by mail, your new registration sticker will arrive by mail within one to two weeks. In-person renewal at an Aurora city office takes about 15 minutes and you receive your sticker when ready. You must display the new sticker on your license plate by the expiration date, or you risk a traffic citation.

Special situations: out-of-state moves and new purchases

If you recently moved to Aurora from another state, you have 90 days from establishing Colorado residency to register your vehicle in Colorado and complete an emissions test. Your out-of-state registration remains valid during that 90-day window. If you buy a used vehicle in Aurora, the seller's current registration and passing test result transfer with the sale, so you do not need to test when ready — you test when that registration expires.

If you buy a vehicle from out of state and register it in Aurora for the first time, you will need to pass an emissions test before you can complete the registration. Plan for this step when budgeting for the purchase, as it adds $20 to $30 and one to two days to the registration process.

Frequently Asked Questions

Can I test my vehicle before my registration expires?

Yes. You can test anytime during your two-year registration cycle. The test result is valid for two years from the test date, so if your registration expires June 15, 2026, you can test as early as June 15, 2024. This is useful if you want to renew early or test during a less busy season.

What if I fail the test and cannot afford repairs?

The Colorado Vehicle Emissions Repair information Program may help cover repair costs if your household income is below a certain threshold. Contact the Colorado Department of Public Health and Environment to learn current income limits and which repairs are covered. Funding is limited and changes year to year.

Do I need to test if I just bought a used car in Aurora?

Not when ready. The seller's passing test result and current registration transfer with the vehicle. You test when that registration expires. If you buy from out of state, you must pass a test before completing your first Colorado registration.

What if my vehicle is too old to test?

Vehicles manufactured before 1975 are exempt from emissions testing in Colorado. Diesel vehicles and motorcycles are also exempt. If your vehicle is exempt, you do not need a test result to renew your registration.

Can I renew my registration without a passing test result?

No. The Colorado Department of Revenue system will not process a registration renewal for a vehicle that requires testing unless a passing test result is on file. You must complete and pass the test before you can renew online, by mail, or in person.