Honestly I've no idea. I've heard of muffs/silencers being gutted but getting the stink out of a cat-box??
Gas emissions testing could be right around the corner everywhere. Having a fully infested fur ball stricken cat-box sitting on the shelf, could be an act of self-preservation. A citation could be in your future. Having the full cat-box reinstalled, pre-court appearance, could be a big savings.
The word I got was, "...I wouldn't screw with it", nationwide enforcement is on the horizon. I keep the box ready for remount. In the out-back areas, where some semblance of freedom still exists, this may be decades away.