Recently I noticed that when I am driving at 60 or so with or without the cruise control the motor will run about 100-150 rpms too high, but if I set the cruise control and then cancel it by tapping the brake and then get back up to my desired speed it will drop down and say at the proper rpms for the speed. It doesn't do it if I cancel the cruise control with the button. Im also getting the P1740 code. Does anyone have any ideas on what exactly the problem could be and how to fix it. I seriously hope this doesn't mean I'll need a new tranny...

 

Test the throttle position sensor first. If that checks ok, replace the TCC, O/D solenoid set. Should take care of it. (but, if it doesn't, implies the torque converter is going bad, and a rebuild is in your very near future.)