Fault code-Secondary air system flow too low

I just got a check engine problem, Peake Research tool shows F5 & F6 which are Secondary Air System Flow Too Low, Cyl #1-3 & 4-6. BMW factory fault code is 245 & 246

Does anyone know what this fault is and what I need to repair or replace to resolve the problem??

Any help would be appreciated.

Thanks to all

YOU MAY NEED AN AIR MASS SENSOR...