I have just postponed my visit to the MB dealer because my 'contact' at the dealership is on leave until next week. In the meantime I have arranged to take it to an Independent for a 'cheaper' assessment on Thursday 24/4/03. Over the phone he pointed to the fault ( I described the gas profile) as potentially being in the lambda circuit and possibly due to either a manifold gasket leak/manifold crack. I had replaced the CAT because of a significant blockage. I wonder if the pressure associated with such a blockage could have blown the gasket at the manifold. Any easy ways to check?
More anon...and certainly after Thursday.