If You Received a Notice to Submit to Testing (NST) Letter
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:
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:
Test Equipment for engine model year 2013 and newer:
Test Equipment for engine model year 2012 and older:
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:
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.