What is the problem that the airflow group 2 of Mercedes-Benz secondary air system is too small?

The problem of secondary air injection valve and pump is that the airflow cylinder group 2 of Mercedes-Benz secondary air system is too small. According to the relevant public information, check whether the air pump works, check whether the lock valve is blocked, check the vacuum tube pressure, check whether the cylinder head is blocked, and finally check the computer and exhaust pipe.