so i have an 03 xb9r with 18,000 miles and lately i have noticed that when i come to a stop every once in a while the idle speed with jump up about 250 rpms and it will sound like its running really poor. if i try to give it gas it will die. i have to just let it sit for a couple seconds and then it will go back to normal. and also when i really get on it, it will fall on its face. it almost seems like its not getting any gas and i dont know if it is my fuel pump or what. it also has aftermarket pipes and a power commander that was on it when i bought it and i have done nothing to it. could it be that? any suggestions?