headers for 2001 boxster?

[Johnny Danger]

Originally Posted by ryuujin

Thanks Daniel and everybody else who replied and assisted.
I thought my 2000 - 2001 boxster had only one set of cats. I was getting a little confused. But Daniel has enlightened me. I am looking at a set of 'Motorsports Downunder' stainless steel headers that the manufacturer assures me will 'just bolt on' with no other mods required. I am curious as to what extra HP and torque I can expect. Should I have it 'retuned or will the headers just work without any tweeking? I was intending to leave the rest of the exhaust standard at this stage - any suggestions?

Ideally, one upgrades the cats along with the headers. Lower cell cats ( say, 200 cell ) definitely improve exhaust flow, while at the same time will retain needed back pressure and shouldn't result in cel's.