--- title: "Clean Truck Check Testers in Walnut, CA (3 listed)" description: "Find 3 CARB-credentialed Clean Truck Check testers in Walnut, Los Angeles County: 3 offer mobile testing, 1 do smoke opacity tests. Phone numbers, services and…" url: "https://ctcfinder.com/testers/los-angeles-county/walnut/" updated: "2026-11-01" publisher: "CTC Finder (independent directory, not affiliated with CARB)" --- # Clean Truck Check testers in Walnut, CA 3 testing businesses in Walnut (Los Angeles County) are on CARB's public Clean Truck Check tester list (4 credentialed testers). 3 offer mobile testing, 1 do smoke opacity tests, 3 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 Walnut - **[Piedra's Smog Test Only](https://ctcfinder.com/tester/piedras-smog-test-only-walnut/)** — 19939 Valley Blvd, Walnut, CA 91789 — (909) 869-8056. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Walnut Smog Center](https://ctcfinder.com/tester/walnut-smog-center-walnut/)** — 319 Lemon Creek Dr Ste L, Walnut, CA 91789 — (626) 202-2827. Services: mobile testing, OBD testing, motorhome testing. - **[Walnut Smog Check Center](https://ctcfinder.com/tester/walnut-smog-check-center-walnut/)** — 319 Lemon Creek Dr Suite L, Walnut, CA 91789 — (909) 594-1913. Services: mobile testing, OBD testing, motorhome testing. ## More testers within 20 miles - **[California CARB Check](https://ctcfinder.com/tester/california-carb-check-west-covina/)** — 2329 E Regina St, West Covina, CA 91792 — (626) 736-7797 — 3 mi. Services: mobile testing, OBD testing. - **[Joseph Avila-Castro](https://ctcfinder.com/tester/joseph-avila-castro-west-covina/)** — West Covina, CA 91792 — (626) 383-3036 — 3 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing. - **[Fridda Vanegas Cabrera](https://ctcfinder.com/tester/fridda-vanegas-cabrera-diamond-bar/)** — Diamond Bar, CA 91765 — (626) 588-7416 — 3 mi. Services: mobile testing, OBD testing. - **[Fleet Cert](https://ctcfinder.com/tester/fleet-cert-west-covina/)** — 521 South Lark Ellen Avenue, West Covina, CA 91791 — (626) 610-8533 — 4 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[CE Logistics](https://ctcfinder.com/tester/ce-logistics-city-of-industry/)** — 915 S Azusa Ave, City of Industry, CA 91748 — (626) 222-6682 — 4 mi. Services: mobile testing, OBD testing. - **[LinkX Logistics Inc](https://ctcfinder.com/tester/linkx-logistics-inc-rowland-heights/)** — 18351 Colima Rd STE 639, Rowland Heights, CA 91748 — (909) 990-8811 — 4 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Marie's cleantruck's check](https://ctcfinder.com/tester/maries-cleantrucks-check-rowland-heights/)** — 19116 E Walnut Dr N, Rowland Heights, CA 91748 — (626) 652-1930 — 4 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Smog Pros Test Only INC](https://ctcfinder.com/tester/smog-pros-test-only-inc-rowland-heights/)** — 18934 Colima Rd, Rowland Heights, CA 91748 — (626) 839-6000 — 4 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Smog Test Only Discount Center](https://ctcfinder.com/tester/smog-test-only-discount-center-rowland-heights/)** — 19116 E Walnut Dr N, Rowland Heights, CA 91748 — (626) 488-2762 — 4 mi. Services: mobile testing, OBD testing, motorhome testing. - **[Rene Quinones](https://ctcfinder.com/tester/rene-quinones-covina/)** — Covina, CA 91724 — (909) 542-5155 — 4 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing. - **[Joe Chavarin](https://ctcfinder.com/tester/joe-chavarin-la-puente/)** — La Puente, CA 91744 — (323) 854-9781 — 5 mi. Services: mobile testing, OBD testing. - **[Jose Carrillo](https://ctcfinder.com/tester/jose-carrillo-la-puente/)** — La Puente, CA 91744 — (626) 251-7676 — 5 mi. Services: mobile testing, OBD testing. ## Trucking in Walnut Los Angeles County has more listed testers than any other county. Seaports and intermodal railyards, including the Ports of Los Angeles and Long Beach, must verify Clean Truck Check compliance at entry or log non-compliant trucks (CARB). ## 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 Walnut? CTC Finder lists 3 testing businesses in Walnut from CARB's public tester list (4 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 Walnut? Yes. 3 listed businesses in Walnut 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 Walnut? 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 - [Rowland Heights](https://ctcfinder.com/testers/los-angeles-county/rowland-heights/) — 4 listings, 4 mi - [West Covina](https://ctcfinder.com/testers/los-angeles-county/west-covina/) — 5 listings, 4 mi - [La Puente](https://ctcfinder.com/testers/los-angeles-county/la-puente/) — 6 listings, 5 mi - [Pomona](https://ctcfinder.com/testers/los-angeles-county/pomona/) — 12 listings, 6 mi - [San Dimas](https://ctcfinder.com/testers/los-angeles-county/san-dimas/) — 4 listings, 7 mi - [Hacienda Heights](https://ctcfinder.com/testers/los-angeles-county/hacienda-heights/) — 4 listings, 7 mi - [Glendora](https://ctcfinder.com/testers/los-angeles-county/glendora/) — 5 listings, 7 mi - [La Habra](https://ctcfinder.com/testers/orange-county/la-habra/) — 6 listings, 8 mi - [Baldwin Park](https://ctcfinder.com/testers/los-angeles-county/baldwin-park/) — 4 listings, 8 mi - [Placentia](https://ctcfinder.com/testers/orange-county/placentia/) — 4 listings, 9 mi