Hi, I was experiencing similar symptoms with my 2003 xtype, i.e.black smoke on hard acceleration and a little hesitation. I changed the air flow meter which cost €90 from Tallaght Autoparts here in Dublin, and hey presto problem solved. The car now drives perfectly. Before you rush out and buy an air flow meter you could disconnect the electrical block from the afm and rev the engine, the black smoke should disappear if the afm is faulty. By doing this simple test the engine management light will more than likely come on and will have to be cleared using a diagnostics.
