--- title: "Clean Truck Check Testers in Sonoma, CA (5 listed)" description: "Find 5 CARB-credentialed Clean Truck Check testers in Sonoma, Sonoma County: 4 offer mobile testing, 3 do smoke opacity tests. Phone numbers, services and…" url: "https://ctcfinder.com/testers/sonoma-county/sonoma/" updated: "2026-11-01" publisher: "CTC Finder (independent directory, not affiliated with CARB)" --- # Clean Truck Check testers in Sonoma, CA 5 testing businesses in Sonoma (Sonoma County) are on CARB's public Clean Truck Check tester list (5 credentialed testers). 4 offer mobile testing, 3 do smoke opacity tests, 4 test motorhomes. > CTC Finder is an independent directory, not affiliated with CARB. Tester data: CARB Clean Truck Check public tester list, last checked November 1, 2026. Confirm services, hours and prices with the tester. ## Testers in Sonoma - **[Carb Tester](https://ctcfinder.com/tester/carb-tester-sonoma/)** — 21707 8th St E, Sonoma, CA 95476 — (707) 772-9077. Services: mobile testing, OBD testing, motorhome testing. - **[Faustino](https://ctcfinder.com/tester/faustino-sonoma/)** — 23195 Maffei Rd, Sonoma, CA 95476 — (707) 953-3466. Services: mobile testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Manzoni Inc](https://ctcfinder.com/tester/manzoni-inc-sonoma/)** — 27500 Skaggs Island Rd, Sonoma, CA 95476 — (707) 996-3685. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Serres corp----CLAYTON](https://ctcfinder.com/tester/serres-corp-clayton-sonoma/)** — 510 Chase St, Sonoma, CA 95476 — (707) 934-7097. Services: OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Shreddy Transport LLC](https://ctcfinder.com/tester/shreddy-transport-llc-sonoma/)** — 1270 Bragg St, Sonoma, CA 95476 — (707) 227-4492. Services: mobile testing, OBD testing. ## More testers within 20 miles - **[Aaron Ramo](https://ctcfinder.com/tester/aaron-ramo-napa/)** — Napa, CA 94559 — (707) 225-7982 — 9 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Jones Family Mobile Diesel Repair](https://ctcfinder.com/tester/jones-family-mobile-diesel-repair-napa/)** — 933 Water St, Napa, CA 94559 — (410) 301-8518 — 9 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Mobile Testing](https://ctcfinder.com/tester/mobile-testing-napa/)** — Napa, CA 94559 — (916) 538-7777 — 9 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Precision Automotive Services](https://ctcfinder.com/tester/precision-automotive-services-napa/)** — 198 Soscol Ave, Napa, CA 94559 — (707) 912-9318 — 9 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Quick Smog](https://ctcfinder.com/tester/quick-smog-napa/)** — 662 Soscol Ave, Napa, CA 94559 — (707) 927-3956 — 9 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Steve DiPiero](https://ctcfinder.com/tester/steve-dipiero-napa/)** — Napa, CA 94559 — (707) 996-3685 — 9 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing. - **[Williams Transmissions and Express Smog](https://ctcfinder.com/tester/williams-transmissions-and-express-smog-napa/)** — 238 Soscol Ave, Napa, CA 94559 — (707) 310-1999 — 9 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Hamilton's Smog](https://ctcfinder.com/tester/hamiltons-smog-novato/)** — 1032 1st St, Novato, CA 94945 — (415) 378-3252 — 10 mi. Services: OBD testing, motorhome testing. - **[ECS Mobile Services](https://ctcfinder.com/tester/ecs-mobile-services-vallejo/)** — 179 Coloma Way, Vallejo, CA 94589 — (707) 398-8574 — 14 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Michael's Transportation Service Inc.](https://ctcfinder.com/tester/michaels-transportation-service-inc-vallejo/)** — 140 Yolano Dr, Vallejo, CA 94589 — (707) 712-6713 — 14 mi. Services: not listed. - **[Alpha Fleet Solutions LLC](https://ctcfinder.com/tester/alpha-fleet-solutions-llc-cotati/)** — 141 Helman Ln, Cotati, CA 94931 — (707) 971-0514 — 15 mi. Services: mobile testing, OBD testing, motorhome testing. - **[CalFleet](https://ctcfinder.com/tester/calfleet-cotati/)** — 7911 Redwood Dr Suite 131, Cotati, CA 94931 — (707) 665-5710 — 15 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. ## Cost Typical published prices in California: OBD test $50–$135 per vehicle; smoke opacity test $190–$200. Prices are set by each tester. ## Frequently asked questions ### How many Clean Truck Check testers are in Sonoma? CTC Finder lists 5 testing businesses in Sonoma from CARB's public tester list (5 credentialed testers), last checked November 1, 2026. Listing on CARB's list is optional, so the real number can be higher. ### Is there mobile Clean Truck Check testing in Sonoma? Yes. 4 listed businesses in Sonoma offer mobile testing, which means the tester comes to your yard. Use the Mobile filter above to see them. ### How much does a Clean Truck Check test cost in Sonoma? Testers set their own prices. Published prices for an OBD test are usually $50–$135 per vehicle; smoke opacity tests for older trucks often cost more, and mobile testers may add a trip fee. See the [cost guide](https://ctcfinder.com/guide/cost/). ### How often does my truck need a Clean Truck Check test? Most trucks test twice a year, on a schedule tied to the DMV registration expiration date. CARB says OBD trucks move to four tests a year beginning October 2027. California-registered (non-commercial) motorhomes and agricultural vehicles test once a year. See the [deadline guide](https://ctcfinder.com/guide/deadlines-2026-2027/). ## Nearby cities - [Napa](https://ctcfinder.com/testers/napa-county/napa/) — 11 listings, 12 mi - [Vallejo](https://ctcfinder.com/testers/solano-county/vallejo/) — 8 listings, 16 mi - [Santa Rosa](https://ctcfinder.com/testers/sonoma-county/santa-rosa/) — 17 listings, 20 mi - [San Pablo](https://ctcfinder.com/testers/contra-costa-county/san-pablo/) — 7 listings, 20 mi - [Fairfield](https://ctcfinder.com/testers/solano-county/fairfield/) — 11 listings, 21 mi - [Richmond](https://ctcfinder.com/testers/contra-costa-county/richmond/) — 3 listings, 22 mi - [Martinez](https://ctcfinder.com/testers/contra-costa-county/martinez/) — 7 listings, 25 mi - [Vacaville](https://ctcfinder.com/testers/solano-county/vacaville/) — 6 listings, 26 mi - [Winters](https://ctcfinder.com/testers/yolo-county/winters/) — 4 listings, 31 mi - [Concord](https://ctcfinder.com/testers/contra-costa-county/concord/) — 7 listings, 31 mi