This might be old news but I've only just stumbled across it.
Basically there was a Ford Technical Service Bulletin relating to 08/09 1.8's re crap injectors, code ending in 3
Mine are '7t1q 9f593 ab' and my symptoms match.
TSB 27/2012 dated 14/05/12 and affects 1.8L Duratorq-TDCi (Lynx) engines between 2008/2009. It affects the Focus, Mondeo, C-Max, Transit connect and Tourneo. The title of the bulletin is "Excessive combustion noise and or hesitation during light load acceleration with the engine at high operating temperature"