Exhaust?

[Wolfinsheepsclothing]

hi Chris,Theo i'm just wanting an opinion on my plans for my exhaust,i currently own a s/c gs and have fitted a kpm cat back,what i was thinking was cutting out the factory cats and welding in some straight through pipes-as this is legal in nz,i know it will need a tune because of the various warning lights,i would value your thoughts,what would be the down sides and would there be any gains,cheerz Geoff