reading some newer topic the other day, and I started to wonder if camcon+exhaust manifold (prolex?)+metallic kat+k&n filter team, all teamed up, could do any good to my poor IS...
Specifically, I don't recall having seen many IS in here with metallic kat... Before I go on and try it myself, maybe with something like this, does any of you have an opinion on this kind of catalysator, and what improvment could they give, paired with an exhaust manifold?