Can you do it: yes

Is it worth it: imo, yes. Cleans up the map, better fuel economy, more response etc. You will get gains, but nothing close to the gains of a full 3" system. However with the stock TD04 on a WRX, I think most would be suprised how close you would get.

Personally if noise is a concern look for Japanese spec JASMA approved exhausts. Normally a 2.5" diameter and are not loud, but flow better than a stock system. I'm a big fan of stealth these days and run a HKS Legamax on my Evo. Loses a few kw compared to a louder system, but sounds close to stock.

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]