--- title: "Clean Truck Check Testers in Modesto, CA (23 listed)" description: "Find 23 CARB-credentialed Clean Truck Check testers in Modesto, Stanislaus County: 21 offer mobile testing, 11 do smoke opacity tests. Phone numbers, services…" url: "https://ctcfinder.com/testers/stanislaus-county/modesto/" updated: "2026-11-01" publisher: "CTC Finder (independent directory, not affiliated with CARB)" --- # Clean Truck Check testers in Modesto, CA 23 testing businesses in Modesto (Stanislaus County) are on CARB's public Clean Truck Check tester list (24 credentialed testers). 21 offer mobile testing, 11 do smoke opacity tests, 17 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 Modesto - **[A&B Truck Repair, Inc.](https://ctcfinder.com/tester/a-and-b-truck-repair-inc-modesto-2/)** — 959 S 9th St, Modesto, CA 95351 — (209) 527-6971. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[A&B Truck repair, Inc.](https://ctcfinder.com/tester/a-and-b-truck-repair-inc-modesto/)** — 959 S 9th St, Modesto, CA 95355 — (209) 527-6971. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Adrian Diaz](https://ctcfinder.com/tester/adrian-diaz-modesto/)** — Modesto, CA 95350 — (209) 621-7691. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Amanpreet Singh](https://ctcfinder.com/tester/amanpreet-singh-modesto/)** — Modesto, CA 95356 — (231) 286-0800. Services: not listed. - **[Brian Padilla](https://ctcfinder.com/tester/brian-padilla-modesto/)** — Modesto, CA 95350 — (209) 918-3600. Services: mobile testing, OBD testing, motorhome testing. - **[CleanTruck209](https://ctcfinder.com/tester/cleantruck209-modesto/)** — 2708 Deerfield Pl, Modesto, CA 95355 — (209) 556-2254. Services: mobile testing, OBD testing, motorhome testing. - **[Independent Fleet Services](https://ctcfinder.com/tester/independent-fleet-services-modesto/)** — 217 Winmoore Way, Modesto, CA 95358 — (209) 529-8106. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[J And L Complete Automotive Repair Inc.](https://ctcfinder.com/tester/j-and-l-complete-automotive-repair-inc-modesto/)** — 711 Kansas Avenue Ext, Modesto, CA 95351 — (209) 480-0010. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Jacob Palleschi](https://ctcfinder.com/tester/jacob-palleschi-modesto/)** — Modesto, CA 95356 — (209) 596-6496. Services: mobile testing, OBD testing. - **[JM Transportation LLC](https://ctcfinder.com/tester/jm-transportation-llc-modesto/)** — 3305 Copeland Ct, Modesto, CA 95355 — (408) 512-7925. Services: mobile testing, OBD testing, motorhome testing. - **[JO Clean Truck Check](https://ctcfinder.com/tester/jo-clean-truck-check-modesto/)** — 2021 Woodland Ave, Modesto, CA 95358 — (209) 326-8839. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing. - **[Jodi Fritz](https://ctcfinder.com/tester/jodi-fritz-modesto/)** — Modesto, CA 95350 — (209) 622-9156. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Linarez Transportatoin LLC](https://ctcfinder.com/tester/linarez-transportatoin-llc-modesto/)** — 1632 Woodworth Ave, Modesto, CA 95351 — (209) 416-9298. Services: OBD testing. - **[Matt Schleiss](https://ctcfinder.com/tester/matt-schleiss-modesto/)** — Modesto, CA 95358 — (209) 480-9556. Services: mobile testing, OBD testing, motorhome testing. - **[Nathan Simpson](https://ctcfinder.com/tester/nathan-simpson-modesto/)** — Modesto, CA 95354 — (209) 678-8549. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing. - **[Nicholas Cuneo](https://ctcfinder.com/tester/nicholas-cuneo-modesto/)** — Modesto, CA 95356 — (209) 518-2215. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Robert Mendes](https://ctcfinder.com/tester/robert-mendes-modesto/)** — Modesto, CA 95357 — (209) 585-6786. Services: mobile testing, OBD testing. - **[S S DPF Filter Cleaning](https://ctcfinder.com/tester/s-s-dpf-filter-cleaning-modesto/)** — 220 Beard Ave, Modesto, CA 95354 — (209) 649-4581. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[S&S dpf filter cleaning](https://ctcfinder.com/tester/s-and-s-dpf-filter-cleaning-modesto/)** — 220 Beard Ave, Modesto, CA 95354 — (209) 622-6134. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Smog & DMV](https://ctcfinder.com/tester/smog-and-dmv-modesto/)** — 1616 Oakdale Rd Suite 1, Modesto, CA 95355 — (209) 735-1241. Services: mobile testing, OBD testing, motorhome testing. - **[Sousa’s Towing LLC](https://ctcfinder.com/tester/sousas-towing-llc-modesto/)** — 1743 Toto Ct, Modesto, CA 95351 — (209) 566-4696. Services: mobile testing, OBD testing, motorhome testing. - **[UPS](https://ctcfinder.com/tester/ups-modesto/)** — 3201 Nightingale Dr, Modesto, CA 95356 — (209) 324-5784. Services: mobile testing, OBD testing, motorhome testing. - **[Walkers Automotive](https://ctcfinder.com/tester/walkers-automotive-modesto/)** — 407 14th St, Modesto, CA 95354 — (209) 527-5577. Services: mobile testing, OBD testing, motorhome testing. ## More testers within 20 miles - **[Freedom smog](https://ctcfinder.com/tester/freedom-smog-riverbank/)** — 2660 Patterson Rd, Riverbank, CA 95367 — (209) 622-9156 — 6 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Amador Castaneda](https://ctcfinder.com/tester/amador-castaneda-salida/)** — Salida, CA 95368 — (510) 266-9595 — 6 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[The Smog GUY](https://ctcfinder.com/tester/the-smog-guy-salida/)** — 5652 Pirrone Rd, Salida, CA 95368 — (209) 812-5206 — 6 mi. Services: OBD testing, motorhome testing. - **[Ace smog](https://ctcfinder.com/tester/ace-smog-ceres/)** — 2500 Mary Ave, Ceres, CA 95307 — (209) 531-6823 — 8 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[All Star Auto Smog](https://ctcfinder.com/tester/all-star-auto-smog-ceres/)** — 1561 E Whitmore Ave, Ceres, CA 95307 — (209) 568-7833 — 8 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Guriqbal Chahal](https://ctcfinder.com/tester/guriqbal-chahal-ceres/)** — Ceres, CA 95307 — (209) 222-0705 — 8 mi. Services: mobile testing, OBD testing. - **[ProMobile Fleet](https://ctcfinder.com/tester/promobile-fleet-ceres/)** — 991 Premier Dr, Ceres, CA 95307 — (209) 769-7925 — 8 mi. Services: mobile testing, OBD testing. - **[Rangi Registration](https://ctcfinder.com/tester/rangi-registration-ceres/)** — 2904 4th St, Ceres, CA 95307 — (209) 480-6516 — 8 mi. Services: OBD testing. - **[Solis Clean Truck Checks](https://ctcfinder.com/tester/solis-clean-truck-checks-ceres/)** — 4467 Faith Home Rd, Ceres, CA 95307 — (209) 996-3687 — 8 mi. Services: mobile testing, OBD testing. - **[Stop Truck Permits](https://ctcfinder.com/tester/stop-truck-permits-ceres/)** — 1320 Tomba Dr, Ceres, CA 95307 — (209) 733-3030 — 8 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Diesel Pollution Solutions](https://ctcfinder.com/tester/diesel-pollution-solutions-keyes/)** — 4928 Audra Ct, Keyes, CA 95328 — (760) 525-9435 — 9 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[A2z Solutions INC](https://ctcfinder.com/tester/a2z-solutions-inc-ripon/)** — Ripon, CA 95366 — (209) 707-9021 — 10 mi. Services: mobile testing, OBD testing, motorhome testing. ## Trucking in Modesto Modesto sits on SR-99 in Stanislaus County, with food-processing and agricultural trucking. Agricultural vehicles test once a year. Stanislaus County (Modesto, Turlock, Ceres) has many food-processing and agricultural fleets on SR-99. ## 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 Modesto? CTC Finder lists 23 testing businesses in Modesto from CARB's public tester list (24 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 Modesto? Yes. 21 listed businesses in Modesto 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 Modesto? 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 - [Ceres](https://ctcfinder.com/testers/stanislaus-county/ceres/) — 7 listings, 8 mi - [Ripon](https://ctcfinder.com/testers/san-joaquin-county/ripon/) — 3 listings, 10 mi - [Escalon](https://ctcfinder.com/testers/san-joaquin-county/escalon/) — 10 listings, 11 mi - [Turlock](https://ctcfinder.com/testers/stanislaus-county/turlock/) — 7 listings, 13 mi - [Oakdale](https://ctcfinder.com/testers/stanislaus-county/oakdale/) — 5 listings, 15 mi - [Manteca](https://ctcfinder.com/testers/san-joaquin-county/manteca/) — 19 listings, 15 mi - [Denair](https://ctcfinder.com/testers/stanislaus-county/denair/) — 4 listings, 20 mi - [Lathrop](https://ctcfinder.com/testers/san-joaquin-county/lathrop/) — 5 listings, 20 mi - [French Camp](https://ctcfinder.com/testers/san-joaquin-county/french-camp/) — 3 listings, 22 mi - [Livingston](https://ctcfinder.com/testers/merced-county/livingston/) — 3 listings, 25 mi