Mercedes E320 1999 sedan

My catalytic converter is making a rattling noise and the car vibrates a bit on idle. Are the two problems related?

Also,I have been told that the cat will eventually need a replacement although it just passed emissions, with mileage at 100,000 miles. Any idea on where i could this job done in Fairfield County, CT or the tristate area at a competent garage with an economical cost?

If you passed emission’s, there’s nothing wrong with the cat. The noise you hear might from a loose heat shield on the cat. But that’s no reason to replace the cat.

Take it to a muffler shop and ask if they can find a loose heat shield. If they do, they’ll either find a way to reattach it, or remove it.


Tester, are you suggesting that the mercedes dealer has probably wrongly diagnosed it as a breakdown of some elements within the cat which are now rattling? Also, should I take it to Meinecke or someone like that or another mercedes dealer, if the work involved is complicated. Thanks

The LAST place you want to take it is the dealer…The most likely cause of the rattle, as Tester said, is a loose heat shield. At a dealership, that’s reason enough to replace the entire exhaust system. Benz Over… Most of todays cars use a stainless steel exhaust that lasts forever. At least, on a Benz, one would hope so…

But first have any local garage take a look at it before you spend serious money on a new exhaust system. If needed, an aftermarket system will be fine…

No matter if it’s heat shield or the cat, your vehicle is old enough where if a cat is needed, an aftermarket cat can be installed at a much lower cost than the dealer. But it doesn’t sound like a problem with the cat. But instead with a heat shield.


Many thanks for the replies received thus far. Does any one know of a reliable local garage in the Fairfield County, CT area who would be able to work on a Mercedes with this type of a problem?