--- title: "Clean Truck Check Testers in Sonora, CA (5 listed)" description: "Find 5 CARB-credentialed Clean Truck Check testers in Sonora, Tuolumne County: 4 offer mobile testing, 1 do smoke opacity tests. Phone numbers, services and…" url: "https://ctcfinder.com/testers/tuolumne-county/sonora/" updated: "2026-11-01" publisher: "CTC Finder (independent directory, not affiliated with CARB)" --- # Clean Truck Check testers in Sonora, CA 5 testing businesses in Sonora (Tuolumne County) are on CARB's public Clean Truck Check tester list (5 credentialed testers). 4 offer mobile testing, 1 do smoke opacity tests, 5 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 Sonora - **[Auto Tech and Tires](https://ctcfinder.com/tester/auto-tech-and-tires-sonora/)** — 18899 Microtronics Way, Sonora, CA 95370 — (209) 743-3699. Services: mobile testing, OBD testing, motorhome testing. - **[Brooke’s Mobile Truck Check](https://ctcfinder.com/tester/brookes-mobile-truck-check-sonora/)** — 20100 Highway 108, Sonora, CA 95370 — (209) 352-6200. Services: mobile testing, OBD testing, motorhome testing. - **[Sundborgs Repair Service](https://ctcfinder.com/tester/sundborgs-repair-service-sonora/)** — 18320 Wards Ferry Rd, Sonora, CA 95370 — (209) 768-7635. Services: OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[TES](https://ctcfinder.com/tester/tes-sonora/)** — 20849 Mechanical Dr, Sonora, CA 95370 — (209) 743-7301. Services: mobile testing, OBD testing, motorhome testing. - **[William Brown](https://ctcfinder.com/tester/william-brown-sonora/)** — Sonora, CA 95370 — (209) 540-7887. Services: mobile testing, OBD testing, motorhome testing. ## More testers within 20 miles - **[A1clean Check](https://ctcfinder.com/tester/a1clean-check-angels-camp/)** — 10668 Oak Valley Rd, Angels Camp, CA 95222 — (209) 630-1490 — 14 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Rorys Fire Apparatus & Diesel Repair](https://ctcfinder.com/tester/rorys-fire-apparatus-and-diesel-repair-angels-camp/)** — 303 N Baker St, Angels Camp, CA 95222 — (209) 628-5674 — 14 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Wayne's](https://ctcfinder.com/tester/waynes-angels-camp/)** — Angels Camp, CA 95222 — (209) 743-8104 — 14 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Coast Machine Inc](https://ctcfinder.com/tester/coast-machine-inc-copperopolis/)** — 5615 Chuckwagon Dr, Copperopolis, CA 95228 — (650) 444-4945 — 19 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 Sonora? CTC Finder lists 5 testing businesses in Sonora 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 Sonora? Yes. 4 listed businesses in Sonora 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 Sonora? 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 - [Angels Camp](https://ctcfinder.com/testers/calaveras-county/angels-camp/) — 3 listings, 14 mi - [Oakdale](https://ctcfinder.com/testers/stanislaus-county/oakdale/) — 5 listings, 27 mi - [Valley Springs](https://ctcfinder.com/testers/calaveras-county/valley-springs/) — 3 listings, 29 mi - [Jackson](https://ctcfinder.com/testers/amador-county/jackson/) — 3 listings, 34 mi - [Denair](https://ctcfinder.com/testers/stanislaus-county/denair/) — 4 listings, 35 mi - [Escalon](https://ctcfinder.com/testers/san-joaquin-county/escalon/) — 10 listings, 38 mi - [Pioneer](https://ctcfinder.com/testers/amador-county/pioneer/) — 4 listings, 38 mi