What is a CTC Certified Tester?

A Clean Truck Check (CTC) Certified Tester is an individual or business authorized by CARB to perform required smog and emissions submissions for non-gasoline heavy-duty vehicles operating in California. Credentialing requires training, equipment, and enrollment in CARB’s Vehicle Information System.

What Certified Testers can do

• Submit OBD compliance tests for 2013 model year and newer heavy-duty diesel vehicles.
• Perform and submit smoke opacity (non-OBD) tests for older heavy-duty diesels.
• Provide testing at a fixed location or, in some cases, as a mobile service.

For-hire vs. private Certified Testers

CARB’s public list only includes for-hire Certified Testers who opted in to public display. Some Certified Testers operate privately for their own fleets and will not appear in this directory.

A faster path: AIRPASS

AIRPASS removes the need to schedule a Certified Tester for routine OBD-eligible submissions. The device handles compliance from inside the truck.

Looking for a Certified Tester near you? Search the directory.