hey. i just installed a tanabe hyper medallion on my 93 non vtec lude but its not the full cat back system just the muffler. well. at first it was nice and quiet and everything and still is but when u give it gas as the rpms drop after the muffler gets soo bassy and vibrates almost the entire car. and its not pleasent for the ears either. what is causing this? i have stock piping size stock cat and resinator

 

install a bigger resonator

or install your oe muffler back...

 

ya i mite have to replace the resonator anyway cuz its all rusted out. but if thats what is causing then great

thanks