P0188 causing stalling?
 

I have a 99 Mystique with the 2.5L V6. Lately we have been having weather in the high 90's and low 100's. Starting with the hot weather, my car has been stalling. Once it cools down at night, it runs with no problems. It will not go past 30 mph and has a hard time getting to second or third gear. I also have to let off the gas in order for it to stall otherwise it will try to keep running but slows down to about 1500 rpms. The P0188 code that showed up says "Fuel Temperature Sensor B Circuit High" however I cannot find any information on where this is located. Any ideas? Thanks in advance!