Can anyone identify this part?

[bladerunner30]

Hi, I'm stripping the engine down to just the bare block from my 1990 UK spec 500se, and I was hoping that someone can tell me what this part is (circled, below), and where does the pipe to the right go, it disapears somewhere under the inlet manifold.



Basically, I need to remove the exhaust manifold, and it looks like this comes off with it, can it be removed without taking off the inlet manifold to get to the other end of the pipe, or should I disconnect it at the exh manifold end and just leave it hanging there?

Cheers, Martin

nb: Usually I'm working on the engine on a stand, it's just on the hoist as I'm trial fitting it into my other Benz....!