I have a 1996 Oldsmobile Cutlass Ciera with a 3.1SFI motor, I am haveing a problem at speeds between 35-40. It seems like it will not shift. This problem has developed after the 1 year warranty on the new transmission has run out. I have replaced a fuel injector that was missfiring, plugs and wires, coils, and Ignition modul but It is still giving me the problem. Any thing that I may have missed. What ever it is it is not tripping the Check Engin Light. Thanks for any info.