My son lost a coil on a 1UZFE (Toy/Lexus DOHC V8) and all that unburned fuel from the left bank went right into the cat where it burned and turned the substrate into charcoal thats bouncing around in there now. Same effect, sounds like a rattle when accelerating or decelerating. Gonna pull it this weekend and try and dump/suck the chunks out with a shop vac. internet pic
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