Emission Control Systems: Testing and Inspection

N52, N52K Engine Primary Catalytic Converters

If the primary catalytic converters are damaged or no longer present, fibres from the mat for the catalytic converter bearing can reach the engine or oil circuit. These fibres can destroy the vacuum pump. In some cases, they can also cause damage to the bearing of the camshaft.
To check the primary catalytic converters in the exhaust manifolds for damage, you first have to unscrew the control sensors.
The graphics below show the configuration of the primary catalytic converters in perfect condition.