The trap oxidizer was something that worked sort of like a catalytic converter. It was used from about 85 to 87 or 88 on diesels sold in the US and was put there to meet California emissions.

They were known for disintegrating and when this happened it would destroy the turbocharger and sometimes do even worse damage than that.

MB went through a campaign to remove them at no cost to the owner. In fact the owner got an ENTIRE new exhaust system from engine to rear bumper at zero cost.

Have a great day,