You can see the linkage and vacuum motor on a 95 by looking under the manifold. The front side opening, by the water pump, has the linkage for the front butterfly array. I can stick my fingers in there and move them. When the engine is running I can see mine open/close when I snap the throttle wide open.
When you push the car hard does it miss or hold back in higher gears and RPMs? Does it knock even with the Techron in the tank? If so, it's leaning out. A lean mixture will knock more and give you lean bank one & two codes. When it's cold the engine needs a richer mixture too. I guessing the fuel pressure is low which can be caused by a bad pump or dirty filter(s).
