To make a long story short about the dealership replacing my LIM gaskets, and horrible gas mileage ever since, I will just say that I went out and discovered that one of my vacuum lines was going from the t valve to nowhere. I believe it is the supercharger bypass line? It is the middle one. Not the big one, or the hard one. The vacuum line runs around the back of the motor and next to the battery then it is unhooked from something, but what? I drive a 2000 Pontiac Grand Prix GTP.
Thanks
also, could that have been affecting my mileage and performance or making a coolant smell?