Hey jay,
Sorry I didn't post the solution to this problem, and glad you brought it to my attention. It's like reading a great book, and the story is building up to some great ending, only to find the last pages missing and never knowing how it ended.
This thread is a continuation of my nightmare with one of my cams. What I THINK was the solution ( it's been a while) but my catalytic converters got plugged up from fuel getting dumped when the pin sheared that kept the cam indexed with the timing belt. I'm not sAying you have a busted cam, but I am saying you may have clogged cats! A decent muffler shop will be able to either remove o2 sensors and check pressures before and after the cats. Or they may also drill small holes before and after the cats, do their test, and then weld the holes shut again. I can't check to see what the codes you are throwing, but if there is extra fuel being dumped down the exhaust, it could be melting down the honeycomb in the cat, and restricting the exhaust. Slow speeds, less pressure, higher speeds, more pressure. And seems that is what I was hearing, that extra pressure escaPing thru the filter box, not a sucking noise, but a blowing noise, and crappy acceleration.

Like I said, it has been a while, and I regret not posting the solution when it was fresh in my mind.
I would quit throwing parts at it for now, and get it to a muffler shop to check the cats. 02 sensors can trigger some codes too and cause poor driving also. And they are not horrible to replace, just something you have to be patent with.... And not do when it's 90+ degrees!