I installed an EAT chip in my 91 M50 5 speed last friday. I don't know if I am imagining it, but at low rpm's in 2nd and 3rd gear (2k and below), I am feeling a strange vibration, and almost a hesitation. Never had these issues before the chip install. Is this normal? Is the advanced timing revealing problems with my motor? Could it be spark plugs, or carbon build up?