Hello, I know nothing about cars and would like some help with my problem. I have a 1996 tahoe (automatic) that idles erratically. It'll jump up while sitting/stopped and a couple times it has stalled. It will also reach between 1400-1600 RPMs and want to shift which makes the engine jump but it doesn't pick up speed and it'll do this several times in a row before it corrects itself. I don't know if this is an inexpensive fix or a expensive transmission repair. I would really like some feedback, thanks.