A4 (B6 AVK) 3.0 petrol inlet manifold/thermostat

[mr_pepps]

Hi,

I was trying to change my thermostat today but couldn't get decent access. Before I gave up becuase it was just too wet and cold to carry on, I think I may have broken the bit shown in the photographs.
Does anyone know what this is, what it does and can it be replaced. Currently my car is undriveable.
This first photo shows the general view i=of the inlet manifold and this weird thing made from black plastic at the front. I undid two bolts to slide this out but didn't release it properly. I think I've broken it. Car makes some nasty noises and misfires when I start it up since putting this plastic thing back on after I partly removed it.

Image below shows a closer shot of the bit I'm trying to identify.
Can it be replaced easily?
I so wish I hadn't tried to move it.

 

[mr_pepps]

I just found out this in the inlet manifold actuator. By the looks of it I think I busted mine by just pulling the end off! I didn't know it was a long cylinder which ran up inside the inlet manifold.
So I guess I'm looking for one of those to replace the one I've broken. And I'll be taking the inlet manifold off properly to remove the broken bits and replace with whatever I can find.
At this stage I'll be able to remove the thermostat housing properly.

Ohhhhhhhhhh boy whay didn't I do this in the first place?!?!?! Aaaarghh!