Ford Focus Forum : “does anyone know if ill get a power increase by decating my st170?if it does the...”

Its possible you would see a couple of bhp.  I think that a cold air intake ( http://www.knfilters.com/air_intake/ford_focus_st170.aspx ) would most likely net about the same gain.  For ideas from some real Focus experts try out http://forums.focaljet.com/  These are true blue focus nuts and will be able to give you real numbers Im sure.