What type of emissions should a fire apparatus with a diesel particulate filter primarily produce?

A fire apparatus equipped with a diesel particulate filter is designed to significantly reduce harmful emissions produced by the engine. The primary function of the diesel particulate filter is to capture and store soot and other particulates from the exhaust system, allowing for cleaner emissions to be expelled into the atmosphere.

When functioning correctly, the apparatus should primarily produce very clean exhaust emissions, which minimizes air pollution and contributes to better air quality. Such emissions consist mainly of nitrogen, carbon dioxide, and water vapor, rather than the soot and particulates that older diesel engines would emit without such filtration technology. This advancement in technology is crucial for fire apparatus, which often operate in urban environments where air quality is a significant public concern.

The other options suggest the presence of pollutants or undesirable indicators of engine inefficiency, which is in direct contrast to the purpose and effectiveness of modern diesel particulate filters.