I had this same problem brotha! Its more than likely something different only because you replaced this part in the past. Some people have replaced theirs 5 times or more. You are not going to like what I am about to say.
IACV
That would be my only guess, the bogging happend to me but it was actually usually around 3k rpms or a little higher. It would like you said -- fall flat on its face.
Maybe run some high quality injector cleaner. I think I heard somewhere that STP makes the good stuff. Check your wires.
[GnuLoCo]
