Look At All Those Clamps On The Rubber Boots Of The Intake Manifold. Make Sure The Clamps And Boots Aren’t Loose, Mis-positioned, Or Separated.
Problems have been found in this area on 2003-2004 Ford Focus models and can cause problems, including rough idle, especially on cold starts.
Ford’s got a Technical Service Bulletin TSB 07-10-7 that addresses this issue.
CSA