Beginning with the fundamentals:
DPF, which stands for Diesel Particulate Filter, functions as a component within the exhaust system. Its primary function is to cleanse soot from the exhaust gases and retain them in a canister.
DEF, short for Diesel Engine Fluid, refers to a urea-based liquid stored in a tank typically located near the diesel filler. Similar to the DPF system, it operates by purifying soot and storing it in an exhaust system canister.
Both systems initiate a regeneration mode to burn off excess soot.
EGR, which stands for Exhaust Gas Recirculation, involves redirecting a portion of the exhaust gas from the combustion chamber back into the intake system. This process is aimed at re-burning the exhaust gas to further cleanse pollutants.
All these systems are integral parts of the emissions systems in modern diesel vehicles and are necessary for vehicles to be road-legal.
What are the downsides of these systems?
Both systems are prone to clogging due to the passage of dirty exhaust gases, which can lead to various issues. A clogged DPF system triggers regen mode in the truck, limiting power and speed while the engine injects diesel to super-heat the chamber, with reported incidents of fires, especially when parked on farm fields during regen mode.
Additionally, both emissions systems introduce extra heat into the exhaust and combustion chamber, diminishing power and increasing fuel consumption.
Extended idling of a diesel engine accelerates the clogging of these systems. Individuals using their trucks for agricultural or racing purposes, exempt from emissions standards, may opt to delete these systems for benefits such as increased power, improved fuel economy, and enhanced reliability with reduced maintenance costs.