Minimum response to the gas peddle. MLCDI 320

What is your question?

Mercedes 320 CDI 2007. When driving down the highway we have a loss of power even though the peddle is touching the floorboard. We had this one other time and it was the fuel filters. They are now trying to sell us on a new oil cooler and torque converter? Is this real What seems to make the problem better or worse? No How long have you had this problem? 2 days