PSIP Advisory 298- Smoke Testing Compliance Categories Topics Enforcement Programs Clean Truck Check (HD I/M) & Periodic Smoke Inspection Programs 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 PSIP Regulation Test Method 435 Automated License Plate Reader