SLK 320 Cats Confusion ...... Help ...!

[Its Nearly Friday]

I have a 2001 SLK 320 and have a rattle underneath the car which has been diagnosed by MB dealer as a dud cat. Usual story it seems after looking on the web. They recommend replacing both and have quoted me 350+ for one side and 600+ for the other side plus labour.
However, when I have looked under the car the 2 cats seem to be in one Y shaped unit. Hence both will be replaced as one. Bottom of the Y goes to the silencer and top of the Y has one side longer than the other - if you follow. Pipe on nearside forward of the cat is longer than pipe on offside forward of the cat. Hence, I am wary of what they are replacing - work being done tomorrow ..!!!! What they have described doesn't fit with what I am looking at but the chap has said they have orderded the part based on the chassis number. Not convinced.
Does anyone out there know the definitive layout of the exhaust and cats .. ? Have tried to find a diagram of the layout but have been unsuccessful. Maybe they are replacing the cats with different pipework. I don't know.
Many thanks.

 

[blassberg]

wow - expensive rattle. Hope you get some help.

 

[Tony]

I've had the same problem - funnily (if that's the right word) on a 2001 SLK320. They broke up first at 15k miles and were replaced under warranty. These cats lasted long enough to get out of warranty and then went again. MB quote £1287 to get them replaced - make sure you get your discount on parts and labour for a 3 year old car. I decided to get after market parts (£400 + £80 labour). All was fine until the "check engine light" came on. Code read "near side cat insufficient capacity". Aaargh! Don't know what to do now. Would welcome suggestions. At the moment I'm driving around with a bright orange warning light on.

As you say MB quote the parts separately but from what I can see they're all one bit. There's a long pipe with a box at the front that goes from the near-side manifold down to the near-side cat. The offside cat is in tandem with the nearside cat but only has a short tube on it - which is presumably connected to the offside manifold using existing pipework. MB only ever replace "both" units - even though in my case it was the nearside cat that had broken up. Offside one was OK.

I'm absoutely sure that these parts are defective, but MB are playing hard ball. I'll never get another Merc. Best of luck.

 

[Its Nearly Friday]

Thanks ...

.... Blassberg & Tony. Tony, you are descrbing the exact same layout so it would seem they can only ever replace both, unless they cut one tube & weld in a new cat. Not the best plan I wouldn't think. I think I will ask to have the car in the air so I can see what has been done. Awaiting phone call.
Suggestion for Blassberg. Cancel your order for a 200 and order a proper one ..!!!!
Cheers

 

[blassberg]

Suggestion for Blassberg. Cancel your order for a 200 and order a proper one ..!!!!

It's a thought..lol... but it's for Mrs B. and she ordered the 200 with 6 sp manual, standard wheels and standard suspension, air scarf, remote fob and most of all heated seats for her 6 mile commute to work.

She didn't order the noisy cat but I suspect that comes as standard.....

 

[Its Nearly Friday]

Update ...

Car now back. Wallet in mourning ...!!!! Seems they actually replace whole exhaust from manifolds back to the join with the single tail pipe. The manifold downpipes have pre-cats in apparently which you can see if you view the manifolds from above. So I guess I could look at it as having 2/3 of a whole new exhaust.
Let me guess .. the rear silencer box if 500 quid ..!!!!!
Looked at a 55 plate 350. Very nice. Seemed that all the dash lit up when I opened the door. Still too expensive so going shopping in the spring.
I did wonder if the 200 was for Mrs B. I bought my 320 for cash after Mrs INF & I got divorced ....!!!!!! Housing market was very good to us ...!!! Bought it back end of 2003. Apparently when guys my age get divorced they go and buy a sports car so thought I'd better follow suit ..!!
Cheers.