Activated Charcoal - Cabin filter 27277-AR225 (which contains a layer of activated charcoal) can be used in place of cabin filter 27277-EG025. The activated charcoal provides additional filtration against objectionable outside odors and pollutants such as hydrocarbons, sulfur dioxide, nitrogen dioxide, and ozone. - The original cabin filter contains a layer of activated charcoal to reduce objectionable outside odors and pollutants such as hydrocarbons, sulfur dioxide, nitrogen dioxide, and ozone. As an economy alternative, cabin filter #27277-EG025 can be used in its place. 27277-EG025 does not contain activated charcoal and filters particulates only. -