It is legit, but please do yourself a favor. Research ECMSpy first, just search for it on this forum. It's not as easy as the guy is making it out to be. Also, please look for the ECMSpy cable on ebay and don't buy from this illiterate moron. Furthermore, if you do decide to get the cable (from him or another person) back up your stock map to a flash drive and keep it away from your computer. This ensures that you can always go back to your original stock map if something goes wrong or you accidentally change a setting and can't remember which one it was. Hope that helps. ECMSpy is a DIY tool to be utilized by those not faint of heart. Good Luck man.