For anybody with the original fast intentions resonated catback that uses the magnaflow muffler as a resonator... It's known that the magnaflow packing will blow out over time.

Mine was loud and raspy sounding. Didn't realize how bad it was until I replaced it. FI used a magnaflow 11386 with the necks cut off. Very easy to cut out and weld in a new one. Night and day difference. Quieter, smoother sounding, and no rasp at all.