The catalytic element is a rock-hard piece of who-knows-what with a bunch of little tiny holes in it. If pieces of the element become dislodged and the holes dont flow air anymore, depending on how big of a piece, I would think it would give too much backpressure. I cleaned out my cats awhile ago and now I am hearing this sound from like my muffler area. It sounds like things are rolling around in the exhaust when I brake. I'm wondering if I missed some element when I cleaned it, or it could be totally unrelated. Does yours sound like that? An offroad h-pipe would be a good addition anyway
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Blueneonman - '95 5.0L Mustang GT Convertible | K&N Custom Cold Air Intake | FMS 9mm Wires | Hollow Cats | Flowmaster 2 Chambers | BBK Subframes | 6-pt Rollcage | 14deg Timing | King Cobra Clutch | FMS Adjustable Clutch Cable | Coolest Neon Lighting on a Mustang EVER!
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