A1 Emissions

Clean Truck Check tester in Simi Valley, CA (Ventura County).

A1 Emissions 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
1933 3rd St, Simi Valley, CA 93065
County
Ventura County
Phone
(805) 857-1085
Mobile testing
Yes — comes to your yard
OBD testing
Yes
Smoke opacity (non-OBD)
No
Motorhomes
Yes
Credentialed testers
1
Last verified

Call (805) 857-1085 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 A1 Emissions can test

The test CARB requires depends on the engine's fuel and model year. Based on the services A1 Emissions 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 Juans Truck Smog in Simi Valley, about 1 mile away. See listing.

Clean Truck Check testers in Ventura County

A1 Emissions is one of 68 testing businesses in Ventura County on CARB's public tester list. 61 of them offer mobile testing and 21 do smoke opacity tests. In Simi Valley itself there are 8 listed businesses, 8 of them mobile. All testers in Ventura 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 A1 Emissions 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 A1 Emissions offer mobile Clean Truck Check testing?

Yes. A1 Emissions 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 A1 Emissions test a 2012 or older diesel truck?

A1 Emissions does not list smoke opacity testing, which older non-OBD diesel trucks need. The nearest listed tester that does is Juans Truck Smog (about 1 mile). Trucks from 2013 on get an OBD scan instead.

How much does A1 Emissions charge for a Clean Truck Check?

A1 Emissions has not published prices with us; call (805) 857-1085 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 A1 Emissions a CARB-credentialed tester?

A1 Emissions 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 Simi Valley

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 (805) 857-1085