My 2.4 is making a buzzing sound when I accelerate. It sounds like it's coming approximately from the exhaust manifold where it connects to the flex downpipe. I already broke the flex pipe thing years ago and I'm guessing this might be it again. To stop it from breaking again I installed the poly motor mounts and that made the motor much stiffer in there so I don't see how it could have broke again. I forgot what the sound was like back then so has anybody broke theirs recently and remember the sound it made? Or is there something else it could be when pressing the accelerator to make a sort of high pitch buzzing? There is no other symptom that I have noticed. Thanks in advance for any input on this.