your cats will be eliminated via a turbo manifold/downpipe, and you'll be needing a 3" exhaust to be open enough for the increased air flow.
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2011 Mustang 5.0 | 3.55's | Lethal Performance off road H-Pipe | Magnaflow Muffler Delete | JLT CAI/Bama tuned 417whp/ 404 ft/lbs
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