Hey there I've been having a problem with my C250 CDI W204 with getting a flatspot in 3rd gear and above between 3k - 4k rpm when im hard on the accelerator. The power only goes away for a second then comes back. The car has had the dpf, cat and egr removed from the system and has been remapped. To start with I thought it was the map so I got the remap removed and tried getting a map done else where. The car does run better on this map but im still get this slight pause in the high gears and high revs. Ive changed the MAP and boost sensors as the diagnostic computer was telling me I had faulty boost sensors. Had turbos inspected and came back fine. Also tried changing the engine relay as this was a fault coming up on the star diagnostics also. I Had it into the garage that remapped it the second time and had smoke tests done on the intake system and vacuum lines (no leaks found) and other checks done like having it on the dyno and checking for the turbo bypass valve opening at high revs and seems to be opening fully and nobody can seem to get their head round the issue. The tuner has also had the map checked and it all looks ok and was told these engines are bad for this because of the change over in the 2 stage turbo but surely in this day and age a twin turbo wouldn't cause this issue. Any help or suggestions are appreciated TIA