I have 2000 Monte Carlo SS 3.8 and my problem is when i wait at a light for a long time my car starts running rough it also happens when I turn the steering wheel too much. it will stop after a while but it will happen again later on.. Any help will be appreciated...

 

Assuming no check engine lights, sounds like a possible need for maintenance. If the plugs and wires are nearing 100K miles on them, time to change. Also cleaning the IAC is a good measure.

Here's some other maintenance items to consider:
https://montecarloforum.com/forum/fw...0-miles-46078/