Are dead CATs noisy ? C200 Auto

[damonp1]

Just had my CAT diagnosed as dead by a Merc specialist. I had took it into an exhaust bay who told me that the system had no leaks but the noise (it sounds like a blown centre pipe) could be the CAT.

Can anyone confirm this ? Why would a faulty CAT make the car sound loud. It is particularly bad when cold then when the car is warm the sound practically goes. Also, will the CAT affect the cars performance. I did not intend to replace it until the next MOT which is Jan 2005.

If the cars peformance can be affected I would be tempted to replace. Does anyone know where I could obtain a universal CAT. I beleive they exist but I cannot find them on the Internet.

Thanks in anticipation of your kind help, comments and, hopefully, advice.

 

[JimmyTD]

If the cat is faulty the ceramic honeycomb usually breaks up causing a rattle and can get dislodged and partially block the exhaust further back and this will affect performance.

I have heard that the engine can suck particles of the broken ceramic back into the engine causing very bad results!!

Any exhaust centre can get a CAT that is designed for your car, they will get them from a local motor factors so you try them direct. I get mine from a company called Fuel Parts not sure if they have a website.

 

[damonp1]

Jimmy

Thanks for the info. Sounds quite serious, particularly the bit about bits getting in the engine.

How would I know if the Cat has disintegrated. i.e. is it possible to have a look at it or will we not know until its replaced. (bit of a doubting Thomas you see).

Thanks a lot

 

[Tony]

As Jimmy said, if the honeycomb breaks up in such a way that it constricts the exhaust it will affect performance. When the cat on my SLK went it didn't seem to have any effect on performance. It just caused an irritating rattling sound at about 2000rpm. Because the dealer took ages to get the part (under warranty) I drove around for about a month with the broken cat. Dealer said nothing about possible damage. It certainly doesn't seem to have done any harm and I think it's fairly unlikely that bits of cat can be sucked into the engine. Engines blow, not suck. I think people are worried about this possibility because cats are now placed much nearer the engine, in order to warm them up more quickly. I still don't think engine damage is very likely - unless anyone knows different.

 

[damonp1]

Thanks Tony.

I think I am now erring towards getting a replacement. Given that the car has done 130.000 I am more inclined to see if I can get a generic replacement or a universal type.

Does anyone know where I could get one. The cheapest I can see on the internet is around £300.00, then I would have to pay for fitting.

Any info would be greatly appreciated.

 

[pluggers]

Does anyone know where I could get one. The cheapest I can see on the internet is around £300.00, then I would have to pay for fitting.

Any info would be greatly appreciated.

Sounds about right for a cheap one,Thats about how much I paid last year £260 inc vat plus about £70 fitting,(I think I got ripped off on the fitting tho)

 

[damonp1]

Thanks for your help