ok, last fall had the rear main oil seal replaced, ever since then, the transmission (while speed shifting) shifts to second gear on its own with the shifter still in first. At regular cruising speed in over drive (usally on inclines) the transmission cuts in and out .. could this be linkage or modualtor valve? this car is a 1997 se.

or could this be an engine break down problem at the rpms of around 2000- 2500 grand or even a possiblly computer breakdown? can anyone please anwser my problem, its been to many shops, no-one can figure it out, forked out lots of money, nothign seems to fix the problem

Your PCM will not allow you to hold 1st gear. Shifting to second is normal (it'* delayed, but it does that to keep you from blowing your motor).

Let'* get into more detail on your OD problem. Surging? Heat related? Fluid color, level, and smell?