Passat b7 shuddering when coasting

[Daveg1007]

Hi all. Newbie here with a 2011 passat b7 estate 140 bluemotion. 90% of the time when driving around town there is no issues but when coasting at speed on the motorway (between 1500 to 2000 revs) the car shudders with the rev counter visibly moves up and down. As soon as the accelerator is pressed is pulls through the shudder no problem. Just doesn't like going at a constant speed when engine is at low revs.

I was thinking a Possible a fuel/air mixture? Faulty EGR, blocked DPF. Had the car read for codes and nothing shows up and no lights on the dash.

Just wondering if anyone has any ideas or things I could try. It's worth noting I had the car revamped and carbon cleaned in december. There was an issue before the remap but does seem to be getting worse.

Thanks

Dave