Location of orifice tube 1998 Cadillac Deville?

The orifice tube on a 1998 Cadillac DeVille is located within the air conditioning system's high-pressure line, usually near the evaporator. It's not easily accessible without removing parts of the A/C system. You won't find it readily visible under the hood. A repair manual specific to your year and model will give you the precise location and details on how to access it.