4 Wheel Drive/SUVs: While driving engine shuts off, 2003 yukon xl, yukon xl

Question
While driving downtown in a large city my 2003 Yukon XL all of the sudden just stops running. I put it in park and turned the ignition it doesn't start, but try it again and it does. After attending my event I was on the way home and about 75 miles down the road it does it again. The engine just stops, I pull over and restart it and it runs fine. The check engine light has been on for awhile and we have taken it to our local mechanic and he hooks it up to his computer and there is an evap sensor that comes up but it doesn't come up with an error. He replaced the fuel filter and cleaned something in the engine and it ran well for about 3 weeks at which time it happened again. This time the engine stayed running, but when I tried to give it gas it wouldn't accelerate. I tried pumping the gas, putting into neutral and pumping the gas, so I pulled over to the side of the road and put it in park and tried pumping the gas and nothing. Turned it off, restarted it, the 2nd time it refired and I drove home. Took to our mechanic and he said he didn't know the cause, but reset the sensor. Any thoughts?

Answer
When it does this and keeps running, does the engine skip real bad or just will not rev up? And not to question your mechanic but it is impossible to "reset" a sensor. You may need to take it to the dealer and have a GM scan tool hooked up to it and it may reveal something that a generic scan tool will not find. Specific manufacturer codes sometimes will not show up on a generic scanner without the right program. The General Motors Tech 2 scan tool is what is needed to see everything

matt