Quote Originally Posted by Scottydoggs View Post
oh, no frigging idea what thats for, i know i didnt take anything like that off my car. sorry, i kept forgetting about it. lol today was a long wet day, im not even settled in yet.
It looks like the seal for the MAP sensor.



And at least on the newer 3800's, they just use the rubber thermostat gasket. Won't hurt to use both I suppose. It will only leak with just the rubber one if you don't get all the corrosion out of the groove.