---
title: "Marquest — Clean Truck Check, Los Angeles, CA | CTC Finder"
description: "Marquest in Los Angeles, CA is on CARB's Clean Truck Check tester list. Offers mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing…"
url: "https://ctcfinder.com/tester/marquest-los-angeles/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Marquest

Clean Truck Check tester in Los Angeles, 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 | 633 W 41st Pl, Los Angeles, CA 90037 |
| County | Los Angeles County |
| Phone | (702) 787-1142 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | Yes |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Marquest 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 Los Angeles County

Marquest 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 Los Angeles itself there are 69 listed businesses, 60 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 Marquest offer mobile Clean Truck Check testing?

Yes. Marquest 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 Marquest test a 2012 or older diesel truck?

Yes. Marquest 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 Marquest charge for a Clean Truck Check?

Marquest has not published prices with us; call (702) 787-1142 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 Marquest a CARB-credentialed tester?

Marquest 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

- **[David Herrera](https://ctcfinder.com/tester/david-herrera-los-angeles/)** — Los Angeles, CA 90037 — (818) 530-6549 — 1 mi. Services: mobile testing, OBD testing.
- **[EJMG Services](https://ctcfinder.com/tester/ejmg-services-los-angeles/)** — 4260 Hooper Ave, Los Angeles, CA 90011 — (213) 364-3555 — 2 mi. Services: mobile testing, OBD testing.
- **[SoCal Smog Testing](https://ctcfinder.com/tester/socal-smog-testing-los-angeles/)** — 5602 S Central Ave, Los Angeles, CA 90011 — (310) 720-6683 — 2 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Walker Mobile CTC](https://ctcfinder.com/tester/walker-mobile-ctc-los-angeles/)** — Los Angeles, CA 90011 — (323) 374-3041 — 2 mi. Services: mobile testing, OBD testing.
- **[Yanes Mobile Services and Repairs](https://ctcfinder.com/tester/yanes-mobile-services-and-repairs-los-angeles/)** — 306 E 50th St, Los Angeles, CA 90011 — (626) 428-1863 — 2 mi. Services: mobile testing, OBD testing.
- **[LA Smog Center](https://ctcfinder.com/tester/la-smog-center-los-angeles/)** — 3671 S Grand Ave, Los Angeles, CA 90007 — (323) 448-7891 — 2 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.