sounds complicated. do note that if you do somehow convert a TRD
kazuma exhaust to comply with both db level limits and emissions requirements..it will not still give you the horses it produced before the cat was on.
personally, unless you are serious about racing (the TRD
kazuma is excellent for that) a much simpler answer would be the greddy evo exhaust (better than average amount of horses/torque..but more importantly it's 50 state legal).