What Is Code P0411 For BMW 325i 2003?

The code P0411 for a BMW 325i 2003 indicates a problem with the secondary air injection system. This system is designed to reduce emissions by injecting fresh air into the exhaust system during engine warm-up. When this code is present, it means that the system is not functioning properly and may require repairs. Common causes of this code include a faulty air pump, clogged air lines, or a faulty air injection control valve.