Hello 

new to the forum and my first post relates to an EGR code that has been diagnosed on my Roomster 1.9 TDI. Valve has been cleaned and stripped down, problem still there. Valve was then replaced with new one, still same problem. Engine runs fine and then into limp mode ..... so mechanic says it could be electrical?? Control unit for the EGR regulates other components apprarenty they’re all ok, so it can’t be control unit. Any ideas most appreciated 

If you are sure all components and control units are fine then wiring or connectors are quite likely to blame. I don't know the details for your car, but pins 4 and 6 are likely the EGR valve pins. Pin 4 should be power feed and 6 should be a ground switched control line.