Could be the A/C
Do you have A/C in your probe?
Let me tell you a "set-back" that I noticed after I had my '97 SE for awhile. I don't have CC, so whenever I travel on highway, I have to have a steady foot (duh). Anyway, I don't have a problem with that, but I noticed after awhile that when I turned the A/C on, I would be going down the highway doing about 65, and then the next time I look down at the speedometer I'm down to 60, and then I would re-adjust my foot to get back up to a steady 65.......only to have it KICK in and then before I know it, I'm up to about 70 or so. At first I thought something was severly wrong, but after I went to our local Ford dealership, they cleared things up.
The reason that they gave me was that because a Probe is only a 4 cylinder and only has about 120-125 HP, it has to give something when teh A/C compresser kicks in. They said that in vehicles with more Horsepower, it's not near as noticable because there is MORE HP to use. However, with the Probe, since it only has about 120 HP to begin with, whenever the A/C compressor kicks in, it draws a good 10-15 HP from the engine, and then when it turn off, you gain that HP back. I thought it was a little annoying at first, but I eventually readjusted.
HOWEVER, if you don't have A/C, I believe that I just wasted about 10 mintues of you life. If that's the case, I'll bet your asking "Why is it that everytime I adhear to your inconsistant rambling you insist on retiring to an advancment of intelectual retardation?"
Hope this helps, because I know it sure was something I would have liked to have known when I first got my Probe.
Has anyone else out there ever had the same problem before? Just wondering......