
From 01:02 to 01:25
A cold start produces pollutants such as carbon monoxide and uncombusted hydrocarbons. The secondary air system is a method of reducing these pollutants. Oxygen-rich ambient air is extracted behind the air filter. This secondary air is blown directly into the exhaust manifold after the exhaust valves.

From 01:25 to 01:40
Burning the pollutants generates heat that brings the catalytic converter up to operating temperature faster.

From 01:40 to 02:00
The central component of the secondary air system is the secondary air pump. Secondary air pumps are high-speed, single or multi-stage blowers.

From 02:00 to 03:00
Secondary air valves have two key functions: As non-return valves, they prevent the exhaust gas condensate and pressure peaks which occur in the exhaust tract from getting into the secondary air pump and damaging it. As cut-off valves, they ensure that air is only supplied to the manifold at the appropriate time.