I have a problem...can anyone advise me on this...

The engine light came on and the error code is PO121...Trottle position sensor...the car has a rough idle when started...then it drives fine until i have to stop at an intersection or robot and then it has a problem taking off...i have to put my foot down totally and then it will take off after a few seconds with a whole lot of speed...

Anyone with ideas for me...