California Air Resources Board

Responding to a Notice to Submit to Testing letter issued by CARB Enforcement under HD I/M. 

To help get your vehicle tested, see the list of commercial CARB-credentialed Clean Truck Check (HD I/M) Testers with contact information: 

• Credentialed Clean Truck Check (HD I/M) Tester and PSIP Smoke Tester Public Lists

For a limited time, if you received an NST letter we are offering a free test and vehicle inspection in Riverside or Fresno, CA. Are you interested? If so, please make an appointment at www.CARBTest.org as soon as you can. This is a limited offer and available appointments will fill up quickly. Remember, if you do not have a test performed by the NST letter deadline, either the free test inspection we are offering or one that you pay for, you could be liable for a Notice of Violation and assessed a penalty.

Alternatively, Clean Truck Check (HD I/M) allows a vehicle owner or a fleet mechanic to conduct the testing and reporting that is required. A tester needs to take the Clean Truck Check (HD I/M) training, pass the exam, and use the correct test equipment, as follows:

• Free on-line Clean Truck Check (HD I/M) Tester Training Course and Exam

Test Equipment for engine model year 2013 and newer:

• CARB-Approved On-Board Diagnostics (OBD) Test Devices

Test Equipment for engine model year 2012 and older:

• CARB-Approved Smoke Opacity Meters

If you are submitting a smoke opacity test for your 2012 or older model year engine, you must also submit a completed Clean Truck Check (HD I/M) Vehicle Emissions Control Equipment Inspection Form:

• Vehicle Emissions Control Equipment Inspection Form

If your vehicle needs repair to demonstrate Clean Truck Check (HD I/M) compliance, you must submit a completed Demonstration of Compliance form (click link below) and send copies of repair receipts.

• Demonstration of Compliance Form

Return to Clean Truck Check (HD I/M) & Periodic Smoke Inspection Programs