Mercedes-Benz ML320 Problems

Exhaust Leak From Front Catalytic Converter on Mercedes-Benz ML320

Problem Description and Possible Solution

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.

(38 people reported this problem)

Mercedes-Benz ML320 Vehicles With This Problem

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Average mileage: 124,331 (54,545–200,000)
6 model years affected: 1998, 1999, 2000, 2001, more2002, 2003
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Viewing 1-17 of 17 comments
loud noise when starting vehicle, sounds like a cheap motorcycle! Calling dealership today for an appointment.
Catalytic converter was replaced. Paid for by dealer, even though I was out of warranty. (apparently it was a known issue)
Small crack on top of cat. Some exhaust leakage, but very minor. Did not affect operation, did not repair.
Check engine light came on and car stalled out. Had it towed to garage and had a cracked catalytic coverter! $1500 paid to install new one! Should Mercedes hav covered this?
Driving on highway doing 80 mph when the engine light comes on and the car slows to 40 mph. Went to a local service station and was told that the real convertor cracked. Both back convertors now need to be repaired at a price of $430 each plus labor.
One of the catalytic converters cracked. The reason is likely the fact that I didn't replace the engine mounts in time and the engine was able to move more that it should. I removed it and brought it to a local shop. The shop owner was able to weld the case back together.
Crack in weld catalytic converter drivers side, just replaced passenger side converter was clogged, $1100 2 months ago. Did not want to spend another $1100 so quick.
Mercedes is an expensive car to maintain, I liked my Jaguar better. If it wasn't for the wife this car would be gone. $150 for oil changes, $300 fix dash lights, bad gas mileage.
Rattle noise took it to exhaust shop fixed it by doing some welding not sure if it's still need service or replacing mercedes should recall this issue !!!
notice a noise getting louder. took it in to Mercedes dealership, 2 hairline cracks. one on each side. have not got repaired yet.
all catalytic converters failed, without know reason or problem. regular scheduled maintenance performed on vehicle
put put sound under car, passed emissions, took to Meta Motors for diagnosis, did not fix, sold car
The passenger catalyctic converter is leaking and starting to leak in the driver's side giving a weird noise.
Couldn't afford to replace it. Did weld it. Now car w/143,000 miles on it and check engine light due to emissions!