Hi CJ

The car would start and after a while die, we had changed fuel and air filters drained the tank (thinking contaminated fuel) it then ran for a short while then died completely...! now 4am so gave up.....
one of the other mechanics took over later in the morning removed the tank and cleaned it! he had no success until he removed the egr valve (seeing the fact that the inlet manifold was restricted by about 50% with crud) It started instantly and is running like a dream with it off... and I mean off, removed , not just the vacuum connection!!
Hence my question the the MB tech. who said that it did no harm if you removed it

ps no warning light, in fact nothing that would make you think there was ever one on.