Anti Pollution fault warning

[labeline]

We have a 59 plate Berlingo XTR 1.6 diesel 90HP. 139k miles. Regularly serviced,Oil change every 6000miles. I had the EGR replaced at the beginning of last year when the old one supposedly failed. The replacement also failed within weeks, so it was replaced again with a better make. Although the fault codes remained in the ECU, the anti pollution warning didn't come up and the Check engine light didn't illuminate. Recently it the anti pollution warning came back up and the EML illuminated.  I checked the codes which all seem to be connected to the EGR valve. I clear the codes, it will last a few days and then the fault returns. The symptoms are always the same. I feel a hesitation while,driving and I know at some point in the drive the warning will come back and the engine management light will come on. As soon as it does, the car drives normally. No loss of power, good acceleration and no other issues whatsoever. Just the EML and the warning. Clear the codes, sometimes 9 sometimes 11 ( don't have them to hand) However they included. P1351, P1162,P0490, P0489,P0409, P1459

It was at the garage earlier this year and he looked at air leaks etc. .....because it smokes when changing gear. He couldn't find anything wrong and suggested changing the EGR again to an OEM one. I am loathe to change it again without being certain that is what the issue is. Is there anything I can do or check to eliminate other issues before I fork for yet another EGR valve?

[Drummond]

Once the EGR was replaced, was the new unit run the learning cycle with the diag tool?