If it was fine why replace the gasket? The book even goes se far as to say it is reuseable; not a wear item.
Might it fit on the engine side of that center gasket?

 

much obliged good sir, it's all welcomed and appreciated.

 

I think this is the answer. Look at the picture of the new part. 3 bumps along the top edge, 3 bumps along the bottom edge, 1 bump on each side edge. This matches with the picture I posted exactly.

A block off plate.

 

Yes, it is exactly the part. My guess is that is a port for EGR or IAC in another application.

 

Please list the codes for us to have a look see, I believe the random plate goes into the place the green gasket goes. I think fastsuv might be able to help with this.

 

Those 2 pictures in posts #2 and #3 are 2 different manifolds. That one picture is a Cobalt manifold ( not sure the year)
I’ve looked at a bunch of HHR parts diagrams. Don’t see that part anywhere.
The OP stated the oil on that part was from his dirty hands ? Should not be a bunch of oil if you’re just replacing an intake manifold gasket.

 

Ok, I found it in this video it’s in the cylinder head were that green oval gasket meets the cylinder head


You can see it herein the head.

Here’s a better view of it

 

A photo of the manifold side which has the green oval gasket

Here ^^^^

 

Thank you very much, for all of the help, and everyone else as well. I figured out everything and also figured out there was a deal of human error in it as well. That piece does indeed go there, it just shows it on no diagram ever, and my air intake ended up melting a hole in it from being so old, so it is now running good as new, as much as a 200K HHR can run. I again thank everyone very much for responding. Atleast 8 people now know what that part is in human existence.

 

glad you're up and running again!