You can change your cabin filter every week. A/C smell, which is a problem on all vehicles, comes from stagnant moisture (mildew) in the air exchange box behind the dash....not from that filter (a charcoal filter may help...Titans isn't that type). You'll notice that you only get the smell for a minute or two when you first turn the AC on, then it subsides. Many places, including some dealers, have a process in which they inject a foaming cleaner into that box..cleaning and sanitizing it to help kill the smell. I don't know how long it'll last though. I've heard that turning the temperature to HOT for a minute before shutting off the truck helps dry any moisture and helps keep that mildew from forming and smelling up the truck again. It was 12* here just a day or so ago. AC is the last thing I'll be using...lol.