Yeah, throttle body. I was in a rush to get this thread posted before company came over and am just now getting back to it. As I was posting earlier, and looking up "stabilitrac, lift gate," and such, a Youtube video suggestion popped up. I had read the other day that if certain things were not jiving, the lift gate would not open so I took a risk and followed the advice of the video. I also know from looking at this issue months ago that the Stabilitrac issue was a "safety" issue that popped up when certain things weren't jiving. Long story short, I replaced the brake light switch. It's late here, midnight, so all I checked was the lift gate: now working.
The hesitation issue was so intermittent that even if I drove it around, I might not could tell if it were fixed or not. I believe it is, but can't verify right now. Here's the vidja:
Thanks guys. I always appreciate any input. Unfortunately when one does not have diagnostics equipment it tends to be a game of hit or miss and could end up costing more in the long run. I know these risks and have accepted them. I had a Jeep XJ for several years. I was always chasing one thing or another down on it. This Tahoe, while not problem free, has tended, so far, to be easier to diagnose and fix.