Mine recently had E3 and E4 codes. The DME was adding fuel due to detected unmetered air past the MAF. Sure enough, an air intake hose connection was loose. Check the intake hose for any loose connections or cracks. Repair as necessary.

I would only worry about the BD code after the first three are fixed. The cats may not be getting hot enough to heat the O2 sensors properly.

Quick search:
BD DME: Insufficient heat output, oxygen sensor before catalytic converter, bank 2

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'06 X5 3.0i - bought @143,123 miles (12/26/20)