My '95 SSEi (168k) has been experiencing a puzzling dilemma for quite some time now.

If I reset the computer (by disconnecting the batter for 15 minutes) my car will purr like a kitten for about a week and a half.

After that it'* hit and miss, but generally experiencing sluggish acceleration. If I repeat the cycle and reset the computer again, I'm rewarded with another week and a half of crisp acceleration and good mileage

I've given it a full tune up, including the front O2 sensor, but not the rear O2 sensor.

I get no check engine lights, but I do have a Traction Control sensor that is not functioning. I don't have the money to fix the traction control, but if it'* the cause of my sluggish acceleration problem, then I'll pony up.

Has anyone had a similar problem?

If I'm not wrong 95 SSEi has only one O2 sensor.
At least I didn't see another one on my SSEi.

You won't want to hear it. But it'* probably a bad pcm. The only true way to find out is replacement. This cures most problems that can't be found on 94/95'*.