Transmission or computer problem?

chevrolet
trailblazer

#1


Three or four months ago, I was driving down the highway when my 2004 Trailblazer seemed to lose accelleration for just a few seconds. The next few seconds it recovered...for just a few seconds... And again it seemed to be just coasting. I tried depessing the accelerator but it acted like it was in neutral. I pulled off to the side of the road, called my husband to come get me, but it took him quite a while and so I tried putting the shift in 3rd gear to see if I could get it to move...it did and I drove home in third gear. I didn't drive for a few days but decided to see what would happen if I drove just around our block. It ran perfectly. I have been driving daily with no more instances until two days ago. Almost the exact same thing happened again. While driving home, I noticed the car was losing speed. I pulled off to the side of the road but this time after about 40 minutes it still would not move in any gear. It happened to be labor day so I called a friend who owns a car lot. The trailblazer was towed to his lot and when they checked it out the next day, there seemed to be nothing wrong with it. They drove it 15 or 20 miles...let it run for an hour to see if that would make something happen. There were no codes when they checked it with the computer. I don't know what to do next. They seemed sure it was not the transmission.

Any ideas...I'm afraid to drive it!