Certified Diesel Emissions Specialist (CDES) The CDES covers diesel aftertreatment systems, selective catalytic reduction (SCR) technology, diesel particulate filters, and on-board diagnostics. You’ll examine emission control strategies across heavy-duty engines, troubleshoot NOx and particulate matter reduction systems, and interpret EPA compliance standards specific to diesel powerplants. Practical knowledge of DPF regeneration cycles and SCR fluid chemistry becomes essential.
| Exam Name | Certified Diesel Emissions Specialist |
| Exam Code | CDES |
| Format | PDF & Practice Test Engine |
| Target Year | 2026 Updated |
| Features | 100% Verified Q&As |
