Valve cover gaskets on v6 vue done.Still have a leak near a/c mounts ?!

I sure did, but I feel like I should have used more now that you mention it. It's just so hard to get under there and see where it may be coming from. New finding! After crawling around and looking for a leak.. I noticed a small 3/8 star bolt with what looks like a rubber grommet approximately 1.5 inches wide going into the engine. This is located directly next to the front converter where it ties into the front exhaust manifold. Any idea what this part is called or any insight to this causing leaks!?!