Guys im still chasing this low power issue below 2500rpm, i had to get my turbo reconditioned not long ago and the car has never been the same after fitting the reconditioned turbo. I did an Air-mass test using ISTA and it suggested there is a problem with my EGR valve, see pic below.

Codes - I get 4D03 exhaust backpressure sensor and 419B ambient pressure sensor. I dont know if these are related to the problem or not.

I sucked on the vacuum hose while connected to the EGR valve and it seems to hold the suction ok. Does this sound ok? Is there a better way to test the egr?

With the engine running i took the hose off the EGR and touched it firmly with my finger end, there is very little suction coming from the Pressure Converter. I then tried the end of the hose before it goes into the Pressure Converter and its actually got a stronger suction than it has after it.. Does this suggest i need to replace the pressure converter?

With regards to the dpf the soot and ash values seem ok. I did 2 x backpressure tests using ISTA and they values were within specs.

I have spent enough on this car recently so i dont want to buy parts on a try it and see basis. Thanks a lot guys