I'm leaning very much towards the DISA, as I can clear those 4 codes, drive for several days and then the codes reappear again (usually after a long hard high speed run going down to normal speed of 40 mph. As I said before, my DISA has been making some noise, and I think that it can affect the O2 sensor circuits if not operating correctly.
Kubica, everything on the SAP circuit is working ok, but extra input is always welcome.
Once I order a new DISA (so it is on hand when I remove and inspect the old one) I will report back to this thread. There is another new thread; Peake E36, E46 Code 19 that has attached 2 video clips of checking and replacing the DISA on an E46.