---
title: "Clean Truck Check Testers in Stanislaus County, CA (53)"
description: "53 CARB-credentialed Clean Truck Check testers in Stanislaus County, California, across 10 cities. 47 offer mobile testing. Search by city, see phone numbers…"
url: "https://ctcfinder.com/testers/stanislaus-county/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Clean Truck Check testers in Stanislaus County, California

53 testing businesses in 10 cities; 47 offer mobile testing, 22 do smoke opacity tests, 34 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.

## City pages

- [Modesto](https://ctcfinder.com/testers/stanislaus-county/modesto/) — 23 listings
- [Ceres](https://ctcfinder.com/testers/stanislaus-county/ceres/) — 7 listings
- [Turlock](https://ctcfinder.com/testers/stanislaus-county/turlock/) — 7 listings
- [Oakdale](https://ctcfinder.com/testers/stanislaus-county/oakdale/) — 5 listings
- [Denair](https://ctcfinder.com/testers/stanislaus-county/denair/) — 4 listings

## Crows Landing

- **[Tonys Truck & Trailer Repair INC](https://ctcfinder.com/tester/tonys-truck-and-trailer-repair-inc-crows-landing/)** — 17055 Crows Landing Rd, Crows Landing, CA 95313 — (209) 485-6665. Services: mobile testing, OBD testing, motorhome testing.

## Keyes

- **[Diesel Pollution Solutions](https://ctcfinder.com/tester/diesel-pollution-solutions-keyes/)** — 4928 Audra Ct, Keyes, CA 95328 — (760) 525-9435. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.

## Patterson

- **[Cencal Mobile CTC](https://ctcfinder.com/tester/cencal-mobile-ctc-patterson/)** — 1386 Toggenberg St, Patterson, CA 95363 — (209) 895-1508. Services: mobile testing, OBD testing, motorhome testing.
- **[Marycruz Angelica Morgado Montiel](https://ctcfinder.com/tester/marycruz-angelica-morgado-montiel-patterson/)** — Patterson, CA 95363 — (408) 401-4856. Services: OBD testing, motorhome testing.

## Riverbank

- **[Freedom smog](https://ctcfinder.com/tester/freedom-smog-riverbank/)** — 2660 Patterson Rd, Riverbank, CA 95367 — (209) 622-9156. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.

## Salida

- **[Amador Castaneda](https://ctcfinder.com/tester/amador-castaneda-salida/)** — Salida, CA 95368 — (510) 266-9595. 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. Services: OBD testing, motorhome testing.

## Trucking in Stanislaus

Stanislaus County (Modesto, Turlock, Ceres) has many food-processing and agricultural fleets on SR-99.

## Frequently asked questions

### How many Clean Truck Check testers are in Stanislaus County?

CTC Finder lists 53 testing businesses in Stanislaus County from CARB's public tester list (54 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 Stanislaus County?

Yes. 47 listed businesses in Stanislaus County 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 Stanislaus County?

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/).