EGR Mounting bolts

[Sciteacher]

I tried to remove my EGR to clean it this afternoon. The top and bottom left hand bolts (viewed from the front) simply spin when I try to loosen them. The right hand ones came out fine. Can anyone cast any light on this? The EGR was replaced just before I had it, around two years ago. My worry is that they might have sheared, but I would be able to pull them out with moles - they don't move.

This is a git, because I'm still getting an 'inlet manifold air leak' message on my OBDII and cleaning the EGR seems like a good place to start (at least according to the guys who looked at it when the problem started).

[Sciteacher]

Sorry. this is in the wrong place - can someone dlete it? I've re-posted in the right place. Sorry!