Aftertreatment Problems New Technology Ends DPF & Emission System Issues in all HD Vehicles; Diesel Progress says: This technology is going to change the way we diagnose and repair heavy duty vehicles. Upstream component faults are the root cause of 89% of aftertreatment problems. Field tests indicate that OEM mandated HD PowerSmoke dramatically cut repair costs and downtime while also increasing fuel economy in HD, Professional Lights, Commercial Sound Equipment ...