What will happen if I have a bad TPS sensor on a dodge stratus 2.4L engine.?

I done a water pump and timing belt. The car starts and the motor sounds good. But it won't idle? After I keep my foot on the gas for about 5 min or so and let off it sound like its going to stall and the revs back up and repeats itself. Can anyone tell me what's wrong with it??
2 answers 2