PSIP Advisory 298- Smoke Testing Compliance Categorías Topics Enforcement Programs Enforcement of Clean Truck Check HD I/M Regulation Tipo Information Advisory 298- Smoke Testing Compliance Advisory, provides information on the proper reading and interpretation of opacity test results using currently available smoke meters for Heavy Duty Diesel Vehicles.Updated 11/20/2019 Related Resources Program Information & FAQs Cargo Tank Certification Decal and Tank Number Display Requirements California State of Emergency (January 7, 2025): Sale, Offer for Sale, and Importation of U.S. EPA Certified Portable Generators into California