Clean Truck Check testers in the San Joaquin Valley

544 testing businesses in the San Joaquin Valley (the Central Valley from Stockton to Bakersfield) are on CARB's public Clean Truck Check tester list, with 565 credentialed testers. 467 (86%) offer mobile testing at your yard, 228 do smoke opacity tests for older trucks and 351 test motorhomes. The largest city pages are Bakersfield (78), Fresno (74), Stockton (50).

Counties in the San Joaquin Valley

Cities with their own page

Smaller cities are listed on their county page.

Testing businesses with several credentialed testers

More credentialed testers usually means more capacity for fleets and before deadlines.

Trucking in the San Joaquin Valley: what to know

The San Joaquin Valley runs along SR-99 and I-5 from Stockton to Bakersfield, with farm, food-processing, dairy, oil-field and long-haul fleets and a growing cluster of distribution centers around Stockton, Tracy and Lathrop. Agricultural vehicles used only in farming test once a year; other trucks follow the normal schedule.

What a Clean Truck Check costs here

Testers set their own prices. Across the California prices we found, an OBD test usually costs $50–$135 per vehicle and a smoke opacity test $190–$200, plus CARB's annual fee ($32.13 in 2026, $33.12 in 2027). Cost guide · Remote and telematics testing.

Frequently asked questions

How many Clean Truck Check testers are in the San Joaquin Valley?

CTC Finder lists 544 testing businesses in the San Joaquin Valley from CARB's public tester list (565 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 the San Joaquin Valley?

Yes. 467 listed businesses in the San Joaquin Valley offer mobile testing, which means the tester comes to your yard. Each city page has a Mobile filter; see also mobile testers.

How much does a Clean Truck Check test cost in the San Joaquin Valley?

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.

Which San Joaquin Valley cities have the most Clean Truck Check testers?

Bakersfield (78), Fresno (74), Stockton (50). Every city with 3 or more listings has its own page with phone numbers and a Mobile filter.

Source: CARB's public Clean Truck Check tester list, last checked . Listing on CARB's list is optional for testers, so some credentialed testers are not shown. Services, hours and prices change; please confirm with the tester before you go. Something wrong? Send a correction.