Car is 1.9 PD130

Car has done 136K and I have done all my own servicing on it since 10K apart from the cambelt changes which I've got the dealer to do, but I have never looked at the EGR valve. My driving is 95% motorway and I have not noticed anything amiss with the way the car runs tick over or moving and still returns around 48 - 50 mpg, but should I remove it and clean it or if no apparent problems leave it alone?

Thanks for your time.

Leave it alone. The only realistic way to stuff it is to do town/taxi driving and/or use dodgy fuel (which is very hard given ULSD unless usage of raw cooking oil is involved )