Mazda 6 2009 2.0D almost no throttle response
 

Hello, sorry for my bad English. I hope you understand my problem.
I have a Mazda 6 2009 2.0 diesel with manual transmission. The summer of 2016 it sometimes had almost no throttle response, could not rev it up. When parked in an underground garage I was not able drive it up hill, it only died. I switched it off and on again, and everything was ok.
In October the problems where worse (but still an intermittent fault) and I took it to the Mazda repairs and they cleaned the diesel filter and the EGR vale. It ran ok for 4 months and then the troubles where back. I again took it to the Mazda repairs, but they could not find anything wrong. I then took it to another repair shop and they said it could be a faulty EGR, but there were no error codes. Mazda charges £500 for the EGR + work, so it is expensive to change if the problem is elsewhere. I have found cheaper EGR on eBay, but for the 2.2D. Is the EGR-valve for 2.0D and 2.2D the same?
Does anyone have any suggestions what might be wrong? I have changed the diesel filter.
Bjørn