It is the EGR valve. Cleaned it and lubed the axle, but no effect. It opens a teeny weeny bit and the low rev respons is gone. Pushed the valve back to closed, mounted it on the manifold, and disconected the contact. Works like a charm! Ignites the "check enigne" light though, but nice to know wwat the problem is.
I'm going to make a plate between valve and manifold just until I get a new EGR. I have the same one as you have with only two pins. I have a OBD reader so I can take away the code later.
Alfa 159 2,4 ti SW 2009