SUBJECT Correct Installation of W20 Catalytic Converter. Metallic noise from rear of vehicle equipped with a range extender. Improperly installed decoupling element allows contact with the heat shield. This may have been the result of a missing or obscured blue mark on the rear silencer support which is meant to indicate how far to push the decoupling element onto the support. This issue is not present from the factory, and is only introduced after previous repairs.
