As Chris155 mentions, there's
Alfadiag. The AlfaDiag site doesn't make it obvious which models are supported. Although the site says "...a diagnostic software solution for Alfa Romeo vehicles built before model year 2001.", the author says that it'll support a 2004 model 156/3.2 and the
FAQ lists the 147/3.2
This interface is said to work fine with AlfaDiag (just ordered one so I'll find out...).
DJ
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