It does not attach to the stock cat.
The Greddy catback or just axleback should bolt right up.
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Current mods: UP/TBE/UTEC/IC Hoses
02 WRX Wagon Silver 214WHP~220WTQ Stage 2+ WRX PICS/ WRX VIDEOS
03 Cobra Convertible Sonic Blue 417RWHP COBRA PICS/VIDEOS