California Clean Truck Check

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Search 2,867 CARB-credentialed testing businesses by city or ZIP code. See who offers mobile testing at your yard, smoke opacity tests for older trucks and motorhome testing.

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2,867testing businesses
2,543offer mobile testing
1,223do smoke opacity tests
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What is Clean Truck Check?

Clean Truck Check is CARB's emissions testing program for heavy-duty diesel and alternative-fuel vehicles over 14,000 lbs GVWR. Each truck must be reported in CTC-VIS, have the annual fee paid ($32.13 in 2026) and pass a test by a CARB-credentialed tester before each deadline: twice a year now, four times a year for OBD trucks from October 2027.

Deadline change: beginning October 2027, OBD-equipped trucks must test four times a year instead of twice. What changes in 2027 · Key facts.

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Who needs a Clean Truck Check?

Nearly all diesel and alternative-fuel vehicles over 14,000 lbs GVWR that operate in California, including out-of-state trucks, buses and California-registered motorhomes. Zero-emission, emergency and military tactical vehicles are exempt.

How often is the test?

Twice a year for most trucks in 2026, tied to the DMV registration date. Trucks with OBD move to four tests a year beginning October 2027. California-registered (non-commercial) motorhomes and agricultural vehicles test once a year.

How much does it cost?

Published prices for an OBD test are usually $50–$135 per truck; smoke opacity tests about $190–$200. CARB's annual fee is $32.13 per vehicle in 2026 and $33.12 for deadlines from January 1, 2027.

Is CTC Finder run by CARB?

No. CTC Finder is an independent directory built from CARB's public tester list. Vehicle registration, fees and certificates are handled only in CARB's CTC-VIS system.

CTC Finder is an independent directory and is not affiliated with CARB. Tester data comes from CARB's public Clean Truck Check tester list (checked November 1, 2026); listing on that list is optional, so some testers may be missing.