98 Jeep, TJ, 4.0, Automatic. >25 degrees F, starts right up runs like it's got 30,000 on the odometer instead of the 198,000 it actually does. 25 to 15 degrees starts but misses and have to feather the accelerator to keep it running for a few minutes then fine. <15 degrees starts, misses, dies, pops through the exhaust like out of time (guessing unburnt fuel hitting hot exhaust), dies, just can't keep running, will restart but just a repeat. I suspect a sensor is not doing it's job but which one would be most likely the issue?