Just had the second Caltalytic Converter changed on my CLK500.

The problem started around 4 months back when a strange grinding sound started coming from the underbody of the car. MB took a look and told me that the problem was with the Catalytic Converter. They replaced the converter and noise was gone.

The same noise started coming again two weeks back. This time the culprit was the left side converter (there happen to be two of them). This one was replaced yesterday and the noise is gone again.

Have any one noticed this thing before. From what I gathered from MB technician, this problem is very much common, particularly in CLKs. It has something to do with high Sulphur content in the Canadian fuels. I am wondering if I'll keep on getting the converter replaced every 10,000 km

 

never heard such thing, catalytic convertors should have a life time of at least 150k km... they are pretty expensive too, i hope you had them replaced from the guarantee... try to get the petrol with highest octane value... that might help..

 

I agree that Catalytic Converters are pretty expensive. And to replace both of them , yeah that looks pretty generous even by Mercedes standards (by the way I have nothing but positive to say about the service I have been provided by Mercedes dealership here in Markham).

I am just copying the exact description of work they have given me on the invoice. They seem to talk about Right Catalyst, and I am not sure if they are talking about the whole Catalytic Converter or not. Here is their description:

A CHECK RATTLE UNDER CHASSIS WHEN IDLE.
CAUSE: NOISY. DIAGNOSE NOISE. REPLACE RIGHT CATALYST
....
495550 CATALYST ON RIGHT SIDE, R&R - REPL IF REQUIRED

On a side note, any of you can comment on 94 Octane fuel and performance effects on our car. Not that I plan to use it on regular basis, but just curious. I might give it a try some time soon.

Thanks,

Zee

 

well I am using 100octane and I love it but I cant say anything coz I had my catalyst removed but I m sure you would be just fine.. higher octane doesnt make any damage, it just lowers the amount of residue... or may be a chemist can explain it better..

 

Just had the right one replaced last week it was under warranty. I was told there are four of them on the clk 320. I drive a 2003 and it has 24,000 miles.

 

Hi OnyxCLK,
Did you experience any problems with teh Engine light coming on after you removed the Cat Converter? Is it louder without it? Power? Thanks!
I'm having the same problem but I can't decide between putting in a High Flow Cat or just removing it all together...