I'm sending this thread as a guide to the numerous people on here who have had this problem. My 04 1.4 tdci fusion suffered a metalic chuffing sound from #3 injector, knowing that the injector seal had gone, my local mechanic said i should go to main dealer and have them fitted as he didnt have the machinery to do the diagnostics if the injectors needed coding. So i went to my main dealer and haggled a price of £235 to replace all four injector seals.I took it in the morning and said i will be back at 4 in the afternoon to pick it up.when i got there it wasnt ready the put the inlet manifold on wrong(how can you do that)!I picked it up the following day. A couple of days later the wife mentined that the car felt flat (lack of power)! i test drove it and it was like the turbo wasn't working, i rang the main dealer told them the situation and had it booked in a few days later!I took it in at 7.45 in the morning by 9.30 they rang me up to say they couldn't find anything wrong with it on the diagnostic machine and there master technichan couldn't find any faulty pipes etc!But the technicichan said it does sound and feel flat on a test drive.So as they couldn't find a fault with there work i owed them £80 for 1hrs labour! so the next thing to do was to pay £100 for ford software so they can check the injectors to see if they were faulty,which the technichan adament that was the problem just how many injectors had gone and the quote would be £1200 inc of vat. i couldn't believe this price and also couldn't believe it was the injectors as there was no smoke of any colour coming from the exhaust or miss firing! so i contacted a few local independent garages to get quotes explaining the situation and two of them said i wont waste your or my time as they were 95% sure its not the injectors.So i went to my trusty local mechanic tonight in desperation for him to look over my car,he went through everything systematically and lo and behold he found a faulty air meter that for some reason had oil on the sensors he cleaned it and now its running like new. The moral of this story is dont take for granted what your main dealer tells you at extortionate prices,sometimes take your car to real mechanics who know how to fix things not fitters(technichans)! lets hope my experiance helps others get a 2nd opinion.