I have the same problem as
@thesmallprint, I had this before. After check engine light went on, and EGR valve was the error that was blocked. I cleared the error 3-4 times, during that time when EGR was blocked, I did not notice any lose in power in light acceleration from 2000-2500 rpm. Suddenly one day I noticed it again, I connected the phone to ECU, and saw that EGR was again in operation(not blocked). (It unblocked itself). After some days I opened EGR myself, and cleaned it completely. Also I noticed that intake manifold had a lot of oiled dust residue, but EGR itself had dry residue. I think this is another problem I have to watch out. Now back to EGR, after I cleaned it, I put it in place. Now I notice from ECU that it opens e closes smoother then before cleaning. BUT time to time I notice the lose of power, I hear the stutter sound like lose of pressure from Turbo and it fills like you breaking in 0.5 second interval. But if you push the acceleration pedal more than that and the EGR goes fully closed, I do not notice any of those things, the acceleration go very smooth.
I do not know what is the fault that does it! I may upload video or photo I capture from phone app, that shows EGR, Pedal %, rpm, power, boost, speed, MAF and Load.