---
title: "Clayton Harkness — Clean Truck Check, Susanville, CA"
description: "Clayton Harkness in Susanville, CA is on CARB's Clean Truck Check tester list. Offers OBD testing. Phone, address and nearby testers."
url: "https://ctcfinder.com/tester/clayton-harkness-susanville/"
updated: "2026-11-01"
publisher: "CTC Finder (independent directory, not affiliated with CARB)"
---

# Clayton Harkness

Clean Truck Check tester in Susanville, CA (Lassen 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 | Susanville, CA 96130 |
| County | Lassen County |
| Phone | (530) 260-1099 |
| Mobile testing | No |
| OBD testing | Yes |
| Smoke opacity (non-OBD) | No |
| Motorhomes | No |
| Credentialed testers | 1 |
| Last verified | 2026-11-01 |

## Which trucks Clayton Harkness 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 | Not listed |

For a 2012 or older diesel, the nearest listed tester with smoke opacity testing is Peterson cat in Susanville, about 1 mile away. [See listing](https://ctcfinder.com/tester/peterson-cat-susanville/).

If you need a tester at your yard, the nearest listed tester that offers mobile testing is Jackson Service Center in Susanville, about 1 mile away. [See listing](https://ctcfinder.com/tester/jackson-service-center-susanville/).

## Clean Truck Check testers in Lassen County

Clayton Harkness is one of 5 testing businesses in Lassen County on CARB's public tester list. 4 of them offer mobile testing and 1 do smoke opacity tests. In Susanville itself there are 4 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 Clayton Harkness offer mobile Clean Truck Check testing?

Not according to CARB's tester list; plan to bring the truck to the tester. The nearest listed mobile tester is [Jackson Service Center](https://ctcfinder.com/tester/jackson-service-center-susanville/) (about 1 mile).

### Can Clayton Harkness test a 2012 or older diesel truck?

Clayton Harkness does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is [Peterson cat](https://ctcfinder.com/tester/peterson-cat-susanville/) (about 1 mile). Trucks from 2013 on get an OBD scan instead.

### How much does Clayton Harkness charge for a Clean Truck Check?

Clayton Harkness has not published prices with us; call (530) 260-1099 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 Clayton Harkness a CARB-credentialed tester?

Clayton Harkness 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

- **[Jackson Service Center](https://ctcfinder.com/tester/jackson-service-center-susanville/)** — 2000 Main St, Susanville, CA 96130 — (530) 815-9139 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[Lassen Transfer & Storage](https://ctcfinder.com/tester/lassen-transfer-and-storage-susanville/)** — 703-750 Richmond Rd E, Susanville, CA 96130 — (530) 251-7073 — 1 mi. Services: mobile testing, OBD testing, motorhome testing.
- **[Peterson cat](https://ctcfinder.com/tester/peterson-cat-susanville/)** — Susanville, CA 96130 — (530) 258-6900 — 1 mi. Services: mobile testing, OBD testing, smoke opacity (non-OBD) testing, motorhome testing.