BMW E46 Misfires

Have encountered the SES light numerous times, going on at least a couple of years.

Error codes that I have encountered

Misfires (all 6 cylinders)
Lean condition
O2 sensors

I’m just spitballing here, these are all worth investigating.

Air and fuel. Are there any vacuum leaks allowing air to enter the system downstream of the MAF sensor?

Inaccurate readings along air path. MAF sensor, O2 sensors

Irregular fuel pressure. Fuel pump, fuel injectors.

Reading Materials:
http://forum.e46fanatics.com/showthread.php?t=897616