hi,
i have already took the centre box out of my exhaust, but im after removing the main cat aswell, now changing the exhaust isnt a problem, but will my car need re-mapping or anything ? just a bit worried about over fueling ect

i have a 2004 blobeye wrx.

and also obviously it will be louder but mainly i am wanting the car to pop and backfire a bit, is there anything else i would have to do to achieve this ? or will the de-cat be enough ?
cheers nick