Catalytic Converters 2003/2004

[BYprodriver]

I am pretty sure all the Aussie & ROW 986 exhaust systems are the same except for the muffler outlet tip. I am more sure it would not be worth the hassle & expense to change the secondary cats. If anything change the manifolds that bolt to the engine to SMALL tube headers for a high rpm power gain & no louder than it is now. Check the part number for Catalytic converters for 99-2003 ROW & see if they are all the same.