This is the EGR and intake flap area on my 606.

http://photos.wanadoo.co.uk/album/1403350

I understand what the EGR and flap do but what does item number 3 do?

Does it also control the flap or is it controlled by the flap It never seems to move even at full throttle so what is its purpose. The pipe from it looks like a vacuum pipe but the nipple it attaches to is solid

If I want to strip and clean the EGR and flap assy are there any danger to watch out for or little gaskets I am going to need to replace on reassembly?

Any advice welcome - I have idling problems which I think are due to crud in EGR or Flap.

Help appreciated
Keith