A friend let me plug his "rich" 2012 mapping plug into my 2009 RMZ 450, just to see what would happen (My only real mod is a Yosh exhaust system). I could swear that the plug gave it a noticeable boost across the bottom/mid, in fact I overjumped a few jumps the first lap with it. I was at the end of the day, it was stupid hot and I didn't have the energy left to go right back out after riding with the plug. It appears that the new one has six wires, while my old one only has four, so I don't see how it could have made a difference.
Was it all in my head?!?