---
title: "Valley SmogWorks — Clean Truck Check, Stevinson, CA"
description: "Valley SmogWorks in Stevinson, CA is on CARB's Clean Truck Check tester list. Offers mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome…"
url: "https://ctcfinder.com/tester/valley-smogworks-stevinson/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Valley SmogWorks

Clean Truck Check tester in Stevinson, CA (Merced County).

> 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.

| Field | Value |
|---|---|
| Location | 19240 First Ave, Stevinson, CA 95374 |
| County | Merced County |
| Phone | (209) 232-5880 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | Yes |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Valley SmogWorks can test

| Your vehicle | Test required | This tester |
|---|---|---|
| Diesel, model year 2013 or newer | OBD scan | Yes |
| Alternative fuel (natural gas, propane), 2018 or newer | OBD scan | Yes |
| Diesel, model year 2012 or older (no OBD) | Smoke opacity test (SAE J1667) plus visual inspection | Yes |
| California-registered motorhome | Same test as above by engine year, once a year | Yes |

## Clean Truck Check testers in Merced County

Valley SmogWorks is one of 40 testing businesses in Merced County on CARB's public tester list. 35 of them offer mobile testing and 12 do smoke opacity tests.

## When your truck is due

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/). You can test up to 90 days before a deadline. Free email reminders: https://ctcfinder.com/reminders/

## Frequently asked questions

### Does Valley SmogWorks offer mobile Clean Truck Check testing?

Yes. Valley SmogWorks says on CARB's tester list that it offers mobile testing, so it can come to your yard or job site. Ask about a trip fee when you call.

### Can Valley SmogWorks test a 2012 or older diesel truck?

Yes. Valley SmogWorks lists smoke opacity testing, the test CARB requires for diesel trucks of model year 2012 and older (no OBD). See [OBD vs smoke opacity](https://ctcfinder.com/guide/obd-vs-smoke-opacity-test/).

### How much does Valley SmogWorks charge for a Clean Truck Check?

Valley SmogWorks has not published prices with us; call (209) 232-5880 for a quote. Published California prices are usually $50–$135 per vehicle for an OBD test and $190–$200 for a smoke opacity test, plus CARB's annual fee ($32.13 in 2026). See the [cost guide](https://ctcfinder.com/guide/cost/).

### Is Valley SmogWorks a CARB-credentialed tester?

Valley SmogWorks appears on CARB's public Clean Truck Check tester list, last checked November 1, 2026. Only credentialed testers can submit results to CARB; after the test, confirm the passing result shows for your vehicle in CTC-VIS.

## Other testers nearby

- **[Gurpreet Atwal](https://ctcfinder.com/tester/gurpreet-atwal-livingston/)** — Livingston, CA 95334 — (209) 913-9160 — 6 mi. Services: mobile testing, OBD testing.
- **[Harpreet Singh Jolly](https://ctcfinder.com/tester/harpreet-singh-jolly-livingston/)** — Livingston, CA 95334 — (559) 999-2732 — 6 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Jorge De La Rosa](https://ctcfinder.com/tester/jorge-de-la-rosa-livingston/)** — Livingston, CA 95334 — (209) 850-1232 — 6 mi. Services: mobile testing, OBD testing.
- **[Hargreaves Ranches LLC](https://ctcfinder.com/tester/hargreaves-ranches-llc-delhi/)** — 17736 Swanson Rd, Delhi, CA 95315 — (209) 988-7214 — 9 mi. Services: mobile testing, OBD testing.
- **[AC AG Services, INC.](https://ctcfinder.com/tester/ac-ag-services-inc-turlock/)** — 605 W Clausen Rd, Turlock, CA 95380 — (209) 678-6867 — 11 mi. Services: mobile testing, OBD testing.
- **[Balswick Quick Smog](https://ctcfinder.com/tester/balswick-quick-smog-turlock/)** — 379 N Golden State Blvd, Turlock, CA 95380 — (209) 216-7132 — 11 mi. Services: OBD testing.