99 monte carlo starts jerking wont throttle

I have a 99 monte carlo ls 3100 engine The check engine light stays on and car starts jerking wont throttle after 3 grand till i let off throttle,Then sometimes it wont do anything and car runs fine.or if im starting to go up a hill it will start too jerk a little then clears up after
 

OK. Check engine light means there is an emission related problem with the vehicle. Go have the codes read and post back here. Please post the EXACT code number so we can help you. Please do not tell us what the person that read the codes told you it was. Some major auto parts houses will read the codes for free.