Replaced bunch of stuff...96 2.4

So I'm back. In another thread I mentioned about some probs I've been having. So because my truck has almost 400k miles, I decided to replace a few things. Injectors, 02 sensors, MAF sensor and a good tuneup.

Went on a trip to Oregon from So Cal and truck ran perfect and got 24 mph. Pretty awesome.

Got back and a couple days ago I drove up to the mountains to check out the snow. Near the top the truck began to hesitate big time. That and low power taking off, smelling like it was running lean. As I headed back down, truck ran better and almost had me fooled.

Back home and getting off the freeway, when I slowed down, truck pulled the same crap. Hesitating, doing the old du duuuu duu duuuuuu duuu as I stepped on the throttle.

What seems to happen is that as zi gradually feather it, and sometimes have to restart it a couple of times, it will begin to run smooth and has almost normal power. But not totallly.

After shutting it down, I have to repeat this process.

Any clues? I'm starting to think that the 45 dollar Amazon MAF sensor is crap.

Ideas?