---
title: "Warner Mountain Smog — Clean Truck Check, Alturas, CA"
description: "Warner Mountain Smog in Alturas, 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/warner-mountain-smog-alturas/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Warner Mountain Smog

Clean Truck Check tester in Alturas, CA (Modoc 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 | 599 Cougar Dr, Alturas, CA 96101 |
| County | Modoc County |
| Phone | (530) 640-3424 |
| Mobile testing | Yes |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | Yes |
| Motorhomes | Yes |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Warner Mountain Smog 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 Modoc County

Warner Mountain Smog is one of 2 testing businesses in Modoc County on CARB's public tester list. 2 of them offer mobile testing and 1 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 Warner Mountain Smog offer mobile Clean Truck Check testing?

Yes. Warner Mountain Smog 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 Warner Mountain Smog test a 2012 or older diesel truck?

Yes. Warner Mountain Smog 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 Warner Mountain Smog charge for a Clean Truck Check?

Warner Mountain Smog has not published prices with us; call (530) 640-3424 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 Warner Mountain Smog a CARB-credentialed tester?

Warner Mountain Smog 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

- **[Daniel Straub](https://ctcfinder.com/tester/daniel-straub-alturas/)** — Alturas, CA 96101 — (530) 708-3562 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.