---
title: "Walnut Smog Check Center — Clean Truck Check, Walnut, CA"
description: "Walnut Smog Check Center in Walnut, CA is on CARB's Clean Truck Check tester list. Offers mobile testing, OBD testing, motorhome testing. Phone, address and…"
url: "https://ctcfinder.com/tester/walnut-smog-check-center-walnut/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Walnut Smog Check Center

Clean Truck Check tester in Walnut, CA (Los Angeles 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 | 319 Lemon Creek Dr Suite L, Walnut, CA 91789 |
| County | Los Angeles County |
| Phone | (909) 594-1913 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | No |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Walnut Smog Check Center 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 Piedra's Smog Test Only in Walnut, about 1 mile away. [See listing](https://ctcfinder.com/tester/piedras-smog-test-only-walnut/).

## Clean Truck Check testers in Los Angeles County

Walnut Smog Check Center is one of 516 testing businesses in Los Angeles County on CARB's public tester list. 465 of them offer mobile testing and 190 do smoke opacity tests. In Walnut itself there are 3 listed businesses, 3 of them mobile.

## 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 Walnut Smog Check Center offer mobile Clean Truck Check testing?

Yes. Walnut Smog Check Center 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 Walnut Smog Check Center test a 2012 or older diesel truck?

Walnut Smog Check Center does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is [Piedra's Smog Test Only](https://ctcfinder.com/tester/piedras-smog-test-only-walnut/) (about 1 mile). Trucks from 2013 on get an OBD scan instead.

### How much does Walnut Smog Check Center charge for a Clean Truck Check?

Walnut Smog Check Center has not published prices with us; call (909) 594-1913 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 Walnut Smog Check Center a CARB-credentialed tester?

Walnut Smog Check Center 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

- **[Piedra's Smog Test Only](https://ctcfinder.com/tester/piedras-smog-test-only-walnut/)** — 19939 Valley Blvd, Walnut, CA 91789 — (909) 869-8056 — 1 mi. 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 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[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.