Changes to the Periodic Smoke Inspection Program (PSIP) and the Heavy-Duty Vehicle Inspection Program (HDVIP) may affect you. The CARB Board approved a new opacity limit of 5 percent for heavy-duty vehicles equipped with diesel particulate filters (DPFs). Other amendments include additional smoke tester training requirements and voluntary submittal of on-board diagnostic (OBD) data in lieu of annual PSIP opacity tests.
The PSIP is an annual self-testing program for smoke opacity and is applicable to California-based fleets of two or more heavy-duty diesel vehicles. HDVIP is a roadside inspection program conducted by the California Air Resources Board (CARB) enforcement staff and is applicable to diesel and gasoline heavy-duty (HD) vehicles operating in California over 6,000 pounds gross vehicle weight rating (GVWR).
Learn more at https://ww3.arb.ca.gov/msprog/truckstop/azregs/opacityfaq.htm