1997 Jeep Grand Cherokee Engine Stalling

I have a 1997 V6 Jeep Grand Cherokee. It's been stalling quite a bit over the past several months. I took it in for service and tuned up the engine. The stalling seemed to go away. Then it started up again. It seemed to be isolated to the first start of the morning. Now it's been stalling like crazy especially when I'm on an incline of any type. I read a blog on a Grad Cherokee stalling with less than 1/4 tank. This doesn't seem to be the problem since it just stalled with a full tank. My mechanic seems to think it's one of the sensors. Any suggestions?

I have had the same problem for a few months now. I took the Jeep to Auto Zone and had a free diagnosis. I forgot what it said, it gave me some code and I have not had the chance to review it.