If no replace cabin air filter in time, the filter will become more clogged with dirt and debris, efficiency A.C system will be compromised and also the bacteria will keep breeding and spread on cabin filter in car compartment will be continually which will lead to the issue of foul odors inside your car. By using 💯% Original DENSO charcoal cabin air filter, not only can block dirt and debris, better at to reduce those foul odors inside car.