My truck has been running great lately and I've been very happy since I worked out most of the little issues. The one thing that has annoyed me is this issue with a hesitation or flat spot when accelerating, and I'm not sure if it is worse or I just notice it more now.

At around 45 or so when accelerating at a decent pace it will hesitate for a second or two and then the power will come back on and it will accelerate as normal. It doesn't do it if accelerating very slowly or under full throttle. At this point I'm not sure if it is actually the engine or the transmission causing it since it almost feels like it is trying to upshift. I've been meaning to record it happen since it is hard to explain, but I keep forgetting to pull my phone out to record it.

Anyone know what might be causing this...throttle position sensor maybe? Just to rule out a few things: MAF has been cleaned; PCV, fuel filter, plugs, and air filter have only a few thousand miles on them.