acdii Report post Posted February 10, 2010 The filter gets dirty, just like that for the engine so it takes longer to move air through the cabin when it gets dirty. You will know for sure you need to change it when the Evaporator for the AC ices up from lack of air flow! In My Hyundai Veracruz, i know it is time to change it now because the auto damper which blocks out exhaust fumes has stopped working. I just cant find one!!!! I cant find one for the Fusion either, whatsupwidat? Quote Share this post Link to post Share on other sites