TIER 4 Interim & Final

Course Date

Coming Soon

Course Length



Course Length: 3 days (8 hrs/day)
Review of system operations for TIER 4 Interim/Final Emissions. Identify the key exhaust emissions being regulated, the timeline for non-road emissions regulations, and the effective dates of each regulation Tier/Stage. Describe CAT solutions for TIER 4 Interim/Final NOx, Hydrocarbon and PM reduction. Summarize the need for, and strategy of, Diesel Particulate Filter (DPF) regeneration and NOx After treatment reduction.

PPE Required

Students must provide their own safety glasses, steel toed footwear, hard hats and fire-retardant coveralls with reflective stripe.


- Proficency with SIS and ET

The following online DPC courses are recommended, but not required:

- Introduction to Tier 3 ACERT Technology Part 1 (WBT) Course 33810
- Introduction to Tier 3 ACERT Technology Part 2 (WBT) Course 33811
- Tier 4 Interim Systems Overview (WBT) Course 33963
- Tier 4 Interim Aftertreatment Service (WBT) Course 33979
- Tier 4 Interim Air Systems Service (WBT) Course 33980
- Tier 4 Interim Regeneration Strategy (WBT) Course 33983
- Tier 4 Interim Regeneration Operator Interface (WBT) Course 33984
- Selective Catalytic Reduction (SCR) and Diesel Exhaust Fluid (DEF) Sales Overview
(WBT) Course 41692


After completion of the course the participant will be able to:
  • Identify the emissions being reduced in Tier IV Interim and Final;
  • Describe Caterpillar’s solutions to reduce emissions for Tier IV Interim and Final; 
  • Locate and identify all the components related to Tier IV Interim and Final on a variety of Caterpillar engines; 
  • Describe the function and purpose of each component on the Tier IV Interim and Final engines; 
  • Trace the exhaust flow in the NOx Reduction System (NRS); 
  • Identify different fuel systems use on Tier IV Caterpillar engines; 
  • Trace fuel flows on each fuel system for Tier IV engines; 
  • Identify and explain the function of the lights and switches as they relate to Tier IV Interim and Final; 
  • Describe the warning methodology as the soot load increases from 0% to 140%; 
  • Identify the different regeneration types and at what soot level they become available; 
  • Explain why Diesel Exhaust Fluid (DEF) was chosen; 
  • Trace the exhaust gas in the Selective Catalytic Reduction (SCR) system; 
  • Describe the process for preventing NH3 slip and NOx slip with in SCR system; 
  • Summarize the safety concerns associated with SCR system.

Successful completion of a written examination with a passing grade of 80%