low rpm/stall when in gear at full stop

Hello, You are likely having issues with your exhaust gas circulation valve, which allows the engine to reduce emissions. If the valve sticks open, it acts like a vacuum leak at idle, and will replicate your condition. You may also just have a vacuum leak, dirty throttle body, or bad idle air control valve, but the timing of the issue makes me suspect the EGR system. Let me know if you have other questions, otherwise, here is a list of certified shops for your convenience. http://repairpal.com/nissan-within-10-miles-of-north-tonawanda-new-york-14120