Is it the zetec or duratech... when i had my 'tour (zetec) i started doing this i brought it to my car guy to pull the codes ( i had a CEL) it was the cam sensor, he changed it and the car still stuttered brought it back again he said that it might be the gas pump so we changed that...to make a long story short i also changed plugs, wires, coil ( they only had maybe 1000 miles) timimg belt. I basically changed everything that had to do with the fuel system and still now improvment.
I did not have any CEL's but the car was still acting up so i went against common sense and brought to ford they told me the car was in perfect condition and could not fine anything wrong with it they even tried with a new MAF and the car still would not run good, i got tired of spending money and not being able to fix the car ( over $2000 in 3 months) and sold the 'tour in mai '03