Well, uh...How about the code, rather than just resetting it before you know whats wrong???
http://www.hstuners.com/forums/showt...threadid=23007
Whatever it is, its putting you into "limp mode", a safety feature that inhibits the car so it doesnt get damaged. Not all cel's will put the car into limp mode, only serious ones (ie not 2ndary o2, iat, etc)
Once you know what the code is, you can go about fixing it.