Thanks for all the advice. After spending a while trawling through the internet I have located the part no 036129061A. It is a vacuum control unit with arm and manged to find one from Autodoc in Germany for £91 delivered. My local Audi dealer in Ipswich was useless telling my mechanic that the part was obsolete and unobtainable. So now ordered and once delivered my car Elliot will not have the dreaded EML light on anymore!