---
title: "Javier Diaz — Clean Truck Check, Gustine, CA | CTC Finder"
description: "Javier Diaz in Gustine, CA is on CARB's Clean Truck Check tester list. Offers mobile testing, OBD testing, motorhome testing. Phone, address and nearby testers."
url: "https://ctcfinder.com/tester/javier-diaz-gustine/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Javier Diaz

Clean Truck Check tester in Gustine, 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 | Gustine, CA 95322 |
| County | Merced County |
| Phone | (209) 342-8445 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | No |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Javier Diaz 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 | Not listed |
| California-registered motorhome | Same test as above by engine year, once a year | Yes |

For a 2012 or older diesel, the nearest listed tester with smoke opacity testing is Enriquez CTC Check in Gustine, about 1 mile away. [See listing](https://ctcfinder.com/tester/enriquez-ctc-check-gustine/).

## Clean Truck Check testers in Merced County

Javier Diaz 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 Javier Diaz offer mobile Clean Truck Check testing?

Yes. Javier Diaz 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 Javier Diaz test a 2012 or older diesel truck?

Javier Diaz does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is [Enriquez CTC Check](https://ctcfinder.com/tester/enriquez-ctc-check-gustine/) (about 1 mile). Trucks from 2013 on get an OBD scan instead.

### How much does Javier Diaz charge for a Clean Truck Check?

Javier Diaz has not published prices with us; call (209) 342-8445 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 Javier Diaz a CARB-credentialed tester?

Javier Diaz 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

- **[Enriquez CTC Check](https://ctcfinder.com/tester/enriquez-ctc-check-gustine/)** — 78 S Mars St, Gustine, CA 95322 — (209) 564-0955 — 1 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Valley SmogWorks](https://ctcfinder.com/tester/valley-smogworks-stevinson/)** — 19240 First Ave, Stevinson, CA 95374 — (209) 232-5880 — 13 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Angel Solache](https://ctcfinder.com/tester/angel-solache-los-banos/)** — Los Banos, CA 93635 — (831) 537-4291 — 14 mi. Services: not listed.
- **[Docs Towing Service](https://ctcfinder.com/tester/docs-towing-service-los-banos/)** — 2710 E Pacheco Blvd, Los Banos, CA 93635 — (209) 619-9717 — 14 mi. Services: mobile testing, OBD testing.
- **[Isaiah Chavez](https://ctcfinder.com/tester/isaiah-chavez-los-banos/)** — Los Banos, CA 93635 — (209) 270-2690 — 14 mi. Services: mobile testing.
- **[Jesus Nava](https://ctcfinder.com/tester/jesus-nava-los-banos/)** — Los Banos, CA 93635 — (209) 649-2304 — 14 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.