Smog & Emission Checks in Colorado

Testing Programs

In certain counties of the state, in order to register and title a vehicle you need to show proof your vehicle successfully passed an emissions test or a basic check.

A complete test, or "enhanced test" is required in Boulder, Broomfield, Denver, Douglas, and Jefferson as well as parts of Adams and Arapahoe counties. Even if you happen to live in a county that does not test, or only has the basic test, yet you commute into these areas, then you also need to pass the enhanced test.

A basic test is required in parts of Larimer, Weld, and El Paso counties. The area boundaries can get confusing, so if you are unclear as to your county's requirements just give the local title and registration office a call.

Enhanced Testing

Envirotest Inc., sporting the name Air Care Colorado, runs the enhanced testing program in the seven areas named above. The company operates 18 centers, open 8 a.m.-5:30 p.m. Monday-Friday and 8 a.m.-1 p.m. on Saturday. If your schedule is tight, you can check current wait times online.

The enhanced or I/M240 test is necessary for all 1982 and newer gasoline-powered passenger cars and light duty trucks and is required every other year. When you receive your registration renewal card in the mail it will specify whether you are due for the test. The fee is $25 payable by cash or check. There are no ATM machines at the test stations.

Vehicles manufactured in 1981 and before and powered by gasoline require a two-speed idle test. This test is offered by Air Care Colorado centers, along with numerous accredited independent inspection facilities. The fee is $15 and the test is valid for only one year. Cash or check only. No credit cards accepted. There are no ATM machines at the test stations.

Note: Newly manufactured vehicles are exempt from emissions requirements for four years. There are various other exemptions including electric and hybrid cars, farm plated vehicles, motorcycles, and pre-1959 cars with collection plates. Check out the complete list.

Rapid Screen Testing

Air Care Colorado has recently implemented a new roadside testing program designed to be an effective alternative to visiting a center and completely free of long waits. The equipment for the program is set up along highway entrance ramps and other sites where a vehicle accelerates uphill, and it involves a van and a highly technological emissions analyzer.

If you pass through one of these areas and manage a clean bill twice in a 10-month period you will receive a passing grade on your registration renewal card. Simply pay the $25/$15 emissions fee with the registration fee and you can avoid a trip to a center.

Basic Testing

Basic tests are available from full-service gas stations, dealerships, and oil change facilities. Fees are $25 for vehicles 1982 and newer (valid two years) or $15 for vehicles 1981 and older (valid one year). Exemptions are the same as for enhanced testing.

Diesel Testing

Diesel vehicles are not inspected by Air Care Colorado but instead fall under the oversight of the Department of Public Health and Environment, and need to be taken to state-certified independent facilities. Fees vary by location and a passing certificate is valid for one year.

New-model, light-duty diesel vehicles are granted a two-year emissions test waiver.

Extensions

Colorado will grant emissions extensions (usually for 12 months) in certain circumstances, including serving in the military or working out of state. Those seeking this service need to complete and mail the application form.

Report a Gross Polluter

Vehicles with smoking tailpipes should not be on the road, and in Colorado there is a way to police these drivers. The next time you spot a smoking vehicle, you have two reporting options through the Colorado Department of Public Health.

The first reporting option is to phone the smoking vehicle hotline at (303) 692-3211. The second option is via e-mail at Smokeline@state.co.us. In both cases, note the type of engine (diesel or gas) and the vehicle's license plate number.

Check out the Denver Metropolitan Pollution Forecast.

Also find Air Care Colorado's tips for vehicle testing and suggestions for vehicles that fail the test.

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