03 MPV loses power after warmup
 

I've been researching all over the place on this and other places, and have been getting a lot of opinions and "solutions" to the problem I am encountering. Runs great on startup, and usually until it's been hot for some time, like an hour or more (heatsoaked?). Then when I try to accelerate there is no power, and if I floor it I can get the engine to downshift and rev up to the redline. This seems to be a chronic problem with these cars, and so far I have seen the following:
Cats plugged
EGR plugged/dirty
Induction hoses off or cracked
plug coils
Engine and chassis grounds
Fuel filters and/or pump
Fuel pressure regulator
I'm sure I've missed some, but you get the point; it doesn't seem as anybody has a clue on how to repair this, or even worse, any and all of these could be the cause. It seemed as though a forum member named babyhuey had some good insights, but he hasn't posted for years. I'm a retired A&P mechanic living in Hawaii, and my experience here is almost all problems are electrical, because of the humidity. So I have dealt with the easiest first, cleaning all the ground connections and confirmed there are no induction issues. But before I jump into changing the cat or whatever I'd like to ask this community if you have any suggestions. I really hate swapping parts to try and fix stuff!