HD I/M Background and Requirements PRINT Date February 14, 2023 Contact HD Vehicle Enforcement Email HDVehicleEnforcement@arb.ca.gov Phone (916) 229-0492 Categories Topics Enforcement Programs Clean Truck Check (HD I/M) & Periodic Smoke Inspection Programs Heavy-Duty Inspection and Maintenance (HD I/M) Regulation: Background and Program Requirements Starting in 2023
