Exhaust System Components

Exhaust System Components

Principle

Due to the rich mixture during the cold start phase, the exhaust emissions contain an increased level of unburned hydrocarbons. The Secondary Air Injection (AIR) system improves the Secondary oxidation within the catalytic converter, thereby reducing harmful emissions. The heat released by Secondary oxidation shortens the startup time of the catalytic converter considerably, as well as significantly improves emissions quality during the cold-running phase.

Function

• During cold start (with coolant temperatures +15 to +35° C), the Secondary Air Injection (AIR) system blows air behind the exhaust valve for approx. 65 seconds. This produces an oxygen rich exhaust gas, causes the after burning and reduces the heating-up phase of the catalytic converter.

• In addition, the Secondary Air Injection (AIR) system is switched on with a delay of approx. 20 seconds during idle for 5 seconds after every subsequent engine start up to max. 80° C coolant temperature and is checked by On Board Diagnostic (OBD).

For all Exhaust System, Emission control component locations.

For all Exhaust System, Emission control removal/installation procedures and torque specifications.

Check the Technical Bulletins for information that may supersede any information included in this information.

• All manufacturers special tools as well as common tools may contain a manufacturer specific part number. These tools may be substituted with an equivalent aftermarket tool or are available for purchase through the manufacturer.

• Manufacturers special tools as well as common tools that contain a manufacturer specific part number may be referenced in the test procedure illustrations showing the tool use or installation. If the manufacturer specific tool is not being used, an equivalent aftermarket tool may be installed in the same manner as the manufacturers special tool.