In this section, the basics of the diesel exhaust system will be covered. From diagrams of exhaust system overviews to the chemical reactions within each portion of the system.

First is the diesel oxidation catalyst (DOC) basics. This portion of the system promotes the chemical oxidation of diesel particulates.

Second, the diesel particulate filter (DPF) basics walk through the function of the DPF and its effect on particulate matter. The DPF is referred to as the “trash can” of the system to remove harmful particles from the air.

Third, we move into selective catalytic reduction. The primary function is to reduce nitrogen oxides from the catalytic system. Nitrogen oxides are incredibly dangerous and decrease air quality.

Fourth is exhaust gas recirculation. This is another portion of the system working to reduce nitrogen oxides.

Fifth is an explanation of how soot and ash load, and plug filter sells.

Sixth, and last we walk about the composition of soot and ash broken down by element.