I'm frustrated on this one..... I will be cruising along the highway and all of a sudden the "RPM'*" will jump up 500 rpm'* and then go back down. Also sometimes it will do the same thing sitting at a light and it will stall. The car always starts back up and has plenty of power. The engine runs great until this happens. I've replaced battery, alternator and O2 sensor. After searching some threads...Could it be the computer or maybe corroded battery cables? Please Help.

welcome to the club, and could you put some info into your signature (make, model , year etc)

sounds like a vacuum problem

I've checked all the vacuum lines and some were split and dryrotted, so I replaced the bad one'*. Forgot to include that in my thread.

Sorry can't figure out how to change member profile...Iam new. 1995 Bonneville 174,000 miles, Block has about 50,000.

I've cleaned the battery cables......I wonder if I should just replace them? The car always restarts after the occasional stall. Engine runs great except once in a while. I've noticed it happens more when its hot outside then when its not, could be coincidental. The reason why I replaced O2 sensor was because a mechanic told me there was a code for rich mixture....FYI.

To change your profile. Look up to the right..near the red car.....click on "Profile" then within the profile..add your year and model to the signature area of the profile.

When my car did that it was the ICM connector that was corroded. On intermitten cases like yours its best to remove all sensor connectors, terminals, grounds, and clean them, sometimes putting them on and off several times re-establishes a good contact.
I have also seen crank sensors cause this when getting hot. The fuel pressure and regulator should also be checked.