i was replacing all my vacuum lines today, and I decide to take off the egr and clean it... you wouldn't believe the amount of carbon build up in the left port(the one that tapers in).  also, i noticed that on the exact opposite side from the diaphram there's a hole in the body of that little circle (just a small ridge against the edge about 1cm long and 1mm wide(the blowout!). 
Anyhow, could this hole in the body of the egr be the cause of my idle surging from 2000rpm to almost stalling then back up? 
is there any epoxy's that could be used to repair this?  or should I just get a new one.
thanks guys.

If the hole is between the EGR and the manifold
it could suck air and cause your idle surge.

If the hole is between the EGR and the manifold
it could suck air and cause your idle surge.

If your looking at the egr module itself, with the diaphram on the right (the way it would mount to the manifold), then the hole is on the left side.  the hole is on the rim of the approx. 3/4" circle (very thin alum. looks as though it's been pressed in.  when i spray cleaner into the larger of the two vacuum ports or the tapered channel connecting to that port then the cleaner comes out the opposite hole and that broke hole as well.

ok, i put some epoxy on the hole and cleaned the egr thoroughly.  I also found a huge hole in the vacuum line that goes from the top center of the manifold to the front most of the two little electrical sensor do-hickey's mounted at the front of the manifold.  So I'll let you guys know if it repairs the surging i was experiencing.  just don't know how long this epoxy takes to cure.  i don't want to suck wet epoxy into the vacuum lines and manifold and permanently gum it up.

Low pressure, epoxy only needs a couple hours (depending on heat / humidity) to set up. For high pressure, I would wait 24 hours.

~J~