I have a 03 wrx, Which I fully decatted two weeks ago. I was worried about over boost and hitting fuel cut with the de cat. I have found the scoob is fine. It boosts a bit more but only to about 1.2 bar.I think this is the best mod I have had done to date. But. You will need a CEL fix.
If you do it, You will think why didnt I do this months ago.