Ok, after much ado I removed the old EGR valve (attached with two bolts), and thoroughly cleaned it with carb cleaner and compressed air, then reinstalled it. Btw, this is a pita job and the bolts seat into aluminum posts (so be careful, I stripped one).

First question: Can a stripped aluminum block bolt hole be fixed?

And I still have high rpm load ticking noise, sounds like a diesel due to the high temp buildup in the manifold...
Any ideas?