Well somthing had to go I suppose, the exhaust pipe has corroded off the back of the cat. I couldn't find many images or info on what to do so I've sourced a new section £127.00 and will attempt to fit it with limited knowledge and skill...

wish me luck I will post hopefully good news.

 

That sucks. You should go to a muffler shop and find out how much a straight pipe retrofit would cost. You'll eliminate your trap oxidizer off the turbo with this option.

 

job done it took three and half hours. the center joint split in the end with the wife standing on it, I had to take the whole section of exhaust off from the joint after the turbo . It wasn't to hard. to split the joint I needed to used mole grips to pull the lock joint together to free it off then it just cane apart. Putting it back together was very tricky but patience and swearing prevailed.
Thanks to mercedes for making things so simply complicated. I think with the right tolls it would be an easy job.
I hope this makes sense writing it after a few beers. current mileage 240,000 miles oh yeah

 

Glad it worked out! Had to learn patiece over time with my BMW and now MB. Did you happen to get a chance to take pics? if so, pls post, curious what the exhaust looks like under there.......

 

sorry did no do pics, from the turbo a small pipe then 2 metal sleeves that clip together hold the center section to the turbo pipe, very simple design and good but a bit tricky to get apart and back together with a pair of pliers.
this goes into a bin shaped chamber and the pipe continues out the bottom and under the car to the rear silencer.
mine corroded from the bottom of the bin piece.

apologies for the techno words but I'm just pretending to be a mechanic.