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Secondary Air Injection

This ECM controlled function remains unchanged from the previous Siemens MS 41.1 system, however there is a hardware change.

The Air Injection Inlet Valve mounts directly to the cylinder head, with a passageway machined through the head. This eliminates the external Air Injection manifold distribution pipes to the exhaust manifolds.

Fig 1: Identifying Secondary Air Injection Valve

Courtesy of BMW OF NORTH AMERICA, INC.