Diesel Emissions Program
Which counties require a passing emissions test to register a vehicle?
- Portions of Adams
- Portions of Arapahoe
- Portions of Larimer
- Portions of Weld
- Portions of El Paso
See our map for testing locations and diesel emissions area boundaries. For hours of operation, please contact the diesel testing station. If you are unsure if a diesel test is required in your area, please contact your local county motor vehicle office.
Frequently Asked Questions (FAQs)
Yes. Effective June 1, 2017 all diesel vehicles that do require a passing emission test (Boulder, Jefferson, Broomfield, Denver and Douglas Counties, and portions of Adams, Arapahoe, Larimer, Weld and El Paso counties) are eligible for online renewal.