Pardon my newbie questions, but I am new to dirt bikes, I have experience with cars and gas R.C. cars, so I'm not totally ignorant. Would just doing the airbox mods be worth it? I'd rather not do the AIS removal because it's not legal here in California, except for closed course competition. What about the grey wire removal and YZ throttle stop mods, would they accomplish anything if I don't do the AIS removal? I did all the Mods but left the AIS on because I made mine street legal and didn't want anyone to blow the whistle on my emissions. The AIS just lets air into the exhaust to completely burn any leftover fuel and has no effect on performance. Now that I am through the DMV and have a plate I might take it off to save weight. I will keep it in a box and put it back on if I hear they are cracking down on emissions. I took off all the smog stuff from my DRZ400S and my Husqvarna TE510 and no one has ever looked for the emissions stuff. The only things that are being checked now in CA are spark arrestors and 96 bdl sound level, no one checks for emissions equipment (not yet).