To begin if you feel like getting into it your self you should get a Chiltons Repair Manual.
Off the top of my head I'd say pull a spark plug or two and check the gap on them..if the gap is way out of spec its time for new AC Declo plugs (Do not use Bosch) When you replace the plugs its a good idea to do the wires too. Taylor makes good wires, same with MSD And AC Delco for our cars. You may want to have a mechanic check your coils..
BUT Get your codes scanned first befor you start leaping into replacing expensive parts!
As for your transmission, check the fluid, What color is it? Red, or more black?
Does it smell like its burnt? If so you might have a problem if not Id look into getting it flushed...if its black and burnt, I wouldnt get it flushed could make the issue worse.
Damien-they don't make them like this anymore
97 SSEi. 3.2mps,msd,optima,1.9 YTs,245 RE750s,SLP Headers,custom ported SC inlet/outlet, 180 deg, INTENSE pcm,42.5#injectors,255lph pump,custom soilid motor mount, 3.0 mps(maybe), and the nut behind the wheel.