I have checked every vacuum line I could find. Replaced them all. The only one I didn't see was one that goes to some sort of canister? I saw it on a diagram online, but I didn't see it on my car - maybe I just missed it.

I cleaned the MAF when I was putting the car back together.

I don't know if this helps or not, but if you lightly hold your foot on the gas, there is no fluctuation whatsoever. But as soon as you let go it resumes trying to die. My gas pedal also seems incredibly easy to depress compared to other GP's I have driven.

Does any of that info help at all?