Could use some help , got a 2008 ltr 450 , got a sudden issue the other day. Bike cut off , no start , red fi light on constant, read code , reading 21 IAT sensor . It will start up with spray in intake but when starts it surges up and down on its own , also when I hit throttle 1/4 of the way it sticks and races at about 1500 rpms, any help appreciated , I see there there is a wealth of knowledge here? Befuddled!!!