The magnaflow competition is essentially a muffler delete. IT sounds good revving and idling, and low rpms. But it sounds kinda ricey going through the rpm range. I had a muffler delete done on my car for about a month before I couldn't take it anymore and took it off. it made me embarrassed of the car. the magnaflow competition series catback I think has glass pack resonators at the axlebacks? i know the axleback doesn't have any resonators.