US spec BMW's have a CEL, Check Engine Light, that turns on when there are codes stored. Did you have a light on dash when you found misfire codes? Need to find out if you have a similar light or if you are suppose to have a similar light. On US cars, running without pre-cat sensors will turn on CEL.
Looks like there was an option for Catalyst delete on your car. See upper right corner of attachments.
Pre-cat O2 sensors may be on backside of exhaust manifold making them difficult to see.