An exhaust leak may develop due to cracked welds on the front catalytic converter. Replacement of the catalyst is recommended; re-welding of the catalyst is discouraged because it is an emissions device.Google+
Car Problem Reports
Mercedes-Benz ML320 Welds May Crack on Front Catalytic Converter
Mercedes-Benz ML320 Problem
Average Mileage: 103,616 mi (54,545 mi - 200,000 mi)
Visitor, 2002 Mercedes-Benz ML320, 150,000 mi
Not covered under recall, have not yet fixed problem. Thinking of welding.
Visitor, 2000 Mercedes-Benz ML320, 54,545 mi
loud noise when starting vehicle, sounds like a cheap motorcycle! Calling dealership today for an appointment.
Visitor, 2000 Mercedes-Benz ML320, 55,000 mi
Catalytic converter was replaced. Paid for by dealer, even though I was out of warranty. (apparently it was a known issue)
Visitor, 2000 Mercedes-Benz ML320, 69,000 mi
The passenger catalyctic converter is leaking and starting to leak in the driver's side giving a weird noise.
Visitor, 2001 Mercedes-Benz ML320, 83,000 mi
center panel covering bubbles and is coming off.
Couldn't afford to replace it. Did weld it. Now car w/143,000 miles on it and check engine light due to emissions!