let us know how you get on,i remember a lad i worked with had an st220 petrol v6 mondeo-it went to ford as it was losing power-first thing they changed was a cat/cats massive bill-no difference,then a sensor or two-same,eventually they changed the fuel pump.was fixed for a while then the new pump failed and had to be replaced by another-he was thousands out for a simple repair
even his symptoms seemed like fuel-iirc he paid them then stopped/froze the payment in some way but still had to fork out a[smaller] fortune in the end