Oscar Diaz
Clean Truck Check tester in Los Angeles, CA (Los Angeles County).
- OBD test
Oscar Diaz appears on CARB's public list of credentialed Clean Truck Check testers. It lists OBD testing.
- Location
- Los Angeles, CA 90002
- County
- Los Angeles County
- Phone
- (330) 409-9181
- Mobile testing
- No (test at the shop)
- OBD testing
- Yes
- Smoke opacity (non-OBD)
- No
- Motorhomes
- No
- Credentialed testers
- 1
- Last verified
Call (330) 409-9181 Open in Google Maps
The street address is not published for this listing (mobile or home-based tester). Call to arrange the test.
Before you call
- Have your VIN, odometer reading and plate number ready.
- Your vehicle must be registered in CTC-VIS and the annual compliance fee paid; the tester submits the result to CARB.
- Ask for the price per vehicle. Typical published prices for an OBD test are $50–$135 per vehicle (see cost guide).
Which trucks Oscar Diaz can test
The test CARB requires depends on the engine's fuel and model year. Based on the services Oscar Diaz lists on CARB's tester list:
| 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 Absolute Inspections in Los Angeles, about 2 miles away. See listing.
If you need a tester at your yard, the nearest listed tester that offers mobile testing is Full Port Diagnostics in Los Angeles, about 1 mile away. See listing.
Clean Truck Check testers in Los Angeles County
Oscar Diaz 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. All testers in Los Angeles County.
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. You can test up to 90 days before a deadline. Get a free email reminder before each one.
How to check a tester's credential
CARB publishes its Clean Truck Check tester list, where Oscar Diaz appears as of November 1, 2026. Listing there is optional, so a missing name does not always mean a tester is not credentialed. After the test, check that the passing result shows for your vehicle in CTC-VIS; that is what counts for compliance.
Frequently asked questions
Does Oscar Diaz 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 Full Port Diagnostics (about 1 mile).
Can Oscar Diaz test a 2012 or older diesel truck?
Oscar Diaz does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is Absolute Inspections (about 2 miles). Trucks from 2013 on get an OBD scan instead.
How much does Oscar Diaz charge for a Clean Truck Check?
Oscar Diaz has not published prices with us; call (330) 409-9181 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.
Is Oscar Diaz a CARB-credentialed tester?
Oscar Diaz 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 near Los Angeles
-
Full Port Diagnostics
- Mobile testing
- OBD test
- Motorhomes
-
Absolute Inspections
- Mobile testing
- OBD test
- Smoke opacity
- Motorhomes
-
Imperialsmog
- Mobile testing
- OBD test
- Motorhomes
-
Jairo Santacruz
- Mobile testing
- OBD test
- Smoke opacity
- Motorhomes
-
U & A Auto Registration Services LLC
- Mobile testing
- OBD test
-
Cz express llc
- Mobile testing
- OBD test
- Smoke opacity
- Motorhomes
Source: CARB's public Clean Truck Check tester list, last checked . Listing on CARB's list is optional for testers, so some credentialed testers are not shown. Services, hours and prices change; please confirm with the tester before you go. Something wrong? Send a correction.