PK - I'll be very interested to hear what your dealer says. I had this
same fault message as, I now understand, have many JTS drivers. In my
case (very common) the car seemed to be otherwise driving normally and
the fault was put down to faulty lamda sensor wiring.

The original wriring is too close to the exhaust manifold and this
sets off the sensor. Alfa have sent a memo to dealers warning them of
this problem. They can re-locate the wiring which seems to solve the
problem.

But, in your case, the car is obviously sick. I recently heard of this
being diagnosed as a plug coil failure but this only proved a
temporary solution and the car had to have one of the lamda sensors
replaced.

It could also be a problem with the fuel injection system. Other
causes I have seen include the fitting of different air filters or
induction systems which make the MCS throw up its hands in horror
because the airflow sensor gets triggered.

In short, plenty of scope for your friendly Alfa "technician"... Best
regards.

Joe