Those are some great numbers... I might take the plunge I was reading about the C230's and the sports package has no resonator and the non-sports package has one. IF mercedes is going to leave it out on the same vehicle with engine just a different package it must not harm anything. I realize its going to provide minimum back pressure but mostly is going to wake it up. Being that MN has laws against pollution but do not inspect or enforce them. Would it be better to remove the rear cats and leave the resonator. Also if I remove the rear cats and run a cross over pipe that should that give me ample amount of back pressure. Second will I trip any codes with the o2's.