Not that I know anything but I have heard that on the new bikes, the rangers, po po or whomever, knows what is supposed to be there and if they see it is all gone you may be ticketed. We must all have clean running and no smog belching dirt bikes out there in the desert. I bet there is a lot more pollution coming from all the weed whippers, blowers and lawn mowers but those are all okay.
Right now I'm not too concerned about the performance of the bike with al that shizzle on it only what will happen in the event it gets torn off, broken, etc. As far as the desert and air quality...the Marines stir up WAAAAAAY more dust than any offroader including any off road event. BUT, acording to the AQMD or ? that has been monitoring the dust levels at 29 palms says differently and that they ARE within their limits. is what I say... em all!