HI I had the same problem with my 2.7 diesel.
what happens is the diesel runs through and blocks up the turbo, injectors , cat etc.
what I did before taking it into the garage is try and run some turbo cleaner through it maybe 2 bottles to try and un block it!
another thing it could be is the actuator on top of the turbo that powers the turbo to work. and on from the 2000 model on wards they put electrical ones on that are common to just disconnect from bad weather and electrical faulty..