What is this piece on the Intake Manifold found in Vortec 5.3/6.0 Engines

[SLAM BAM]

I'm looking over the intake manifold and noticed that a piece of it is melted. I'm neither its function or what it is.

This is the picture of the piece. It's not my picture; like I wrote, the one on my intake is melted in.

Someone looks like they may have plastic welded it? I'm not sure. Maybe this is related to the knock sensor problem?

Will I need to order a new intake manifold?

 

Here's another picture.

[txab]

It's a potential source of vacuum if required. It's not used from the factory and in normal operation you'll not use it.

 

 

[Ianf]

If the tab on that connector breaks off and the port opens you will get a lean fuel code and need yo put a cap on it. My 2010 tab got knocked off by my mechanic while changing the plugs and we put a cap on the port.

 

[SLAM BAM]

I think whoever owned this truck before probably got a lean code and decided to plastic-weld this piece on forever. Thanks for the responses guys.