If your not starting in low gear check the little snow flake button next to the gear shift. If this has been pressed your starting in 3 rd. gear.
I would guess that is for the "sport" mode. That is correct. If pushed it will hold what ever gear you are in to hold until you shift to another higher gear. It won't allow the transmission to shift.
My '97 won't shift out of 1st gear when its cold (it will after it warms up). I found that pushing the "S" button will enable it to shift when cold. It has worked every time so far.
Your Transmission
The S button on top of the gear shifter stands for sport mode. it makes the car shift smother in faster take off
The cost of fixing the transmission on a 1998 cadillac catera with the 3rd gear nearly burnt out was approximately $2000.
Vaccum leak or bad gas!
Trouble code P0730 means:Incorrect gear ratio
The high preasure goes from the pump to the gear and the return goes from the gear to the pump resirvoir.
it sets your transmission in winter mode, meaning you are taking off in a higher gear.
sports mode it supposeably changes the shifting points to make it accelerate faster
its the bitsi cylinoid in your gear shift which allows u to take the car out of park when u engage the brake u need to replace your gear shift assembly i just replaced mine 400 bucks
LIFT THE RUBBER PIECE UNDER THE CIGARETTE LIGHTER WHERE U WOULD PUT CHANGE THERE IS A YELLOW BUTTON UNDER THERE PUSH IT FOWARD AND SHIFT YOUR GEAR I HAD THE SAME PROBLEM