It collects warm air to be sucked into the intake. They come with a flexible tube that runs from the heat shield to the airbox and when you first start the car it is supposed to suck air from it to warm the engine up faster. I hear its a completely unessecary system - therefor it should be fine.
took mine off when i did my intake about 4 months ago, and nothing happened. Also i would have had to take it off when i did my header swap anyways, so its basically pointless
Yep, it's an old school choke stove system, providing warm air to the intake during cold start. Probably has some small affect on increasing cold gas mileage, as well as cold start driveablilty.
I was amazed to find one on my 89. I hooked everything back up so that it works. I see no advantage to removing it on a daily driver.
If you remove it, make sure to remove and plug all of the vacuum lines.