---
title: "Marathon Smogs — Clean Truck Check, South Gate, CA"
description: "Marathon Smogs in South Gate, 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/marathon-smogs-south-gate/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Marathon Smogs

Clean Truck Check tester in South Gate, 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 | South Gate, CA 90280 |
| County | Los Angeles County |
| Phone | (424) 449-8273 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | Yes |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Marathon Smogs 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

Marathon Smogs 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 South Gate itself there are 13 listed businesses, 9 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 Marathon Smogs offer mobile Clean Truck Check testing?

Yes. Marathon Smogs 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 Marathon Smogs test a 2012 or older diesel truck?

Yes. Marathon Smogs 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 Marathon Smogs charge for a Clean Truck Check?

Marathon Smogs has not published prices with us; call (424) 449-8273 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 Marathon Smogs a CARB-credentialed tester?

Marathon Smogs 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

- **[Chris Ancheta](https://ctcfinder.com/tester/chris-ancheta-south-gate/)** — South Gate, CA 90280 — (562) 612-2847 — 1 mi. Services: mobile testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Dieseltester](https://ctcfinder.com/tester/dieseltester-south-gate/)** — 9706 Pinehurst Avenue, South Gate, CA 90280 — (323) 240-0943 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[Ebenezer Mobil Repair](https://ctcfinder.com/tester/ebenezer-mobil-repair-south-gate/)** — 5120 Firestone Pl, South Gate, CA 90280 — (562) 280-9075 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[Eddie’s Clean Truck Test](https://ctcfinder.com/tester/eddies-clean-truck-test-south-gate/)** — 9305 Mallison Ave, South Gate, CA 90280 — (209) 793-2040 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[Eduardo Soria](https://ctcfinder.com/tester/eduardo-soria-south-gate/)** — South Gate, CA 90280 — (323) 567-8842 — 1 mi. Services: OBD testing, smoke opacity (non-OBD) testing, motorhome testing.
- **[Gabriel Garcia Jr](https://ctcfinder.com/tester/gabriel-garcia-jr-south-gate/)** — South Gate, CA 90280 — (323) 561-2055 — 1 mi. Services: OBD testing.