Q: P1138 nissan sentra 1.8 code reads where is the swirl sensor located the car stalls upon acceleration or rpm revels then drops

The swirl control valve is actually a part that helps to control the vaporization of the fuel inside the intake passages as it is passed through to the combustion chamber during low idle or cooler operating temperatures. As you may know, when the engine is at idle or when it is running at a cooler operating temperature, the air fuel mixture does not vaporize quite as quickly or efficiently as it does when the engine is warm or at higher speeds an generating more velocity. This valve closes during lower idle speeds and cooler temperatures to help increase this velocity effect, resulting in a more efficiently burned air/fuel charge. When this valve is not working as it is designed to, you may notice the engine running a bit rough or causing the check engine light to come on as you describe. I would suggest having a professional from YourMechanic come to your location to inspect and replace this valve.