Alright I have a 96 thunderbird with the 3.8 with 165000miles on it. When i start it up when its cold it will idle smooth. When placed in drive the car want to run ruff and want to stall. When the car warms up its having the opposite issue. The idle goes up to around the 1800rpm range and makes the car hard to slow down and hold at a stop. i had it in the shop yesterday and they were telling me i need an intake gasket set? Any advice would be greatly appreciated!! Thanks