K&N Flat Panel filter on WRX

[BALISTC]

Before the turbo, in the exhaust manifold, is a catalytic converter..

Dont ask me why Subaru put one in there, but its the stupidest idea I've ever heard of.

To get maximum power gains out of the new age WRX, this up pipe before the turbo has to be changed at the same time as the exhaust and the computer.

[rexxxy]

Pre Turbo cat is there to meet strict US emission Laws.

[SDU4EVA]

If you ever get rid or the air intake resonator MSR make a very good cold air intake pipe to replace it that runs down to collect cold air and its only 100bucks I think.
Naturally you can make your own alot cheaper.