I have just resolved and long annoying problem. My 2014 MT-09 has 44k on it. It started to feel like it did when it was new and had nasty throttle response prior to the reflash recall. The bike has Kev's O2 mod and used to be smooth. The bike was tiring to ride in traffic and generally unpleasant. Anyway after several visits to the mechanic it finally threw a fault code. "Throttle body needs cleaning". This problem was in play for two months before the fault code told the mechanic what to do. They cleaned it and it's all good now. I would suggest getting this done at the 40k service while they are in there dong the valve clearances.