Walnut Smog Check Center

Clean Truck Check tester in Walnut, CA (Los Angeles County).

Walnut Smog Check Center appears on CARB's public list of credentialed Clean Truck Check testers. It lists mobile testing, OBD testing, motorhome testing. Mobile testing means the tester can come to your yard or job site.

Location
319 Lemon Creek Dr Suite L, Walnut, CA 91789
County
Los Angeles County
Phone
(909) 594-1913
Mobile testing
Yes — comes to your yard
OBD testing
Yes
Smoke opacity (non-OBD)
No
Motorhomes
Yes
Credentialed testers
1
Last verified

Call (909) 594-1913 Open in Google Maps

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 and any mobile trip fee. Typical published prices for an OBD test are $50–$135 per vehicle (see cost guide).

Which trucks Walnut Smog Check Center can test

The test CARB requires depends on the engine's fuel and model year. Based on the services Walnut Smog Check Center lists on CARB's tester list:

Your vehicleTest requiredThis tester
Diesel, model year 2013 or newerOBD scanYes
Alternative fuel (natural gas, propane), 2018 or newerOBD scanYes
Diesel, model year 2012 or older (no OBD)Smoke opacity test (SAE J1667) plus visual inspectionNot listed
California-registered motorhomeSame test as above by engine year, once a yearYes

For a 2012 or older diesel, the nearest listed tester with smoke opacity testing is Piedra's Smog Test Only in Walnut, about 1 mile away. See listing.

Clean Truck Check testers in Los Angeles County

Walnut Smog Check Center 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 Walnut itself there are 3 listed businesses, 3 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 Walnut Smog Check Center 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 Walnut Smog Check Center offer mobile Clean Truck Check testing?

Yes. Walnut Smog Check Center 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 Walnut Smog Check Center test a 2012 or older diesel truck?

Walnut Smog Check Center does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is Piedra's Smog Test Only (about 1 mile). Trucks from 2013 on get an OBD scan instead.

How much does Walnut Smog Check Center charge for a Clean Truck Check?

Walnut Smog Check Center has not published prices with us; call (909) 594-1913 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 Walnut Smog Check Center a CARB-credentialed tester?

Walnut Smog Check Center 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 Walnut

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.

Call (909) 594-1913