The opti for a 97 is the same as a 1994.5 and up. Starting in 96, GM put a separate sensor in the (3rd version) timing chain cover for diagnostic purposes. It has nothing directly to do with, and isn't part of the opti.

 

if you can find a place with a diognostic code reader that would be best, that way if theres a code for the trany in there it will show. check all your plug wires to make sure they are on all the way, also check the coil wire to make sure its on all the way to. i am thinking the motor is misfiring and causing the problem. could be running rich, might be a good idea to pull a couple plugs to see if they are fouled, black, if so that may be the cause of the misfire. if it is the tcc i would think you would have a code for it.

 

I'd check the sparks and wires I had teh same problem i got it fixed by replacing all the ignition coils on my car

 

Another recommendation for a scan

 

Turns out that fuel pump was starting to crap out, not holding enough PSI.