Ok the symptoms.
1. Low power in the upper rpm range (3.5k-up) with a large increase in intake volume, and change in exhaust tone.
2. Almost normal power in low rpm range (idle to 3.5k) with slight increase in intake noise and almost silent exhaust.
3. Cranks and idles normally, in both cold high idle and warm low idle.
4. No milkshake in oil and the plugs look ok, slightly brown in color.
5. No CEL, burning rubber smell when i came off interstate, no smoke, no noises.
6. Warm idle vacuum is around 17 inches with about 3/4 inch of needle shake, when the rpm is increase the vacuum drops but rises back fairly quick and stays dead steady at any rpm. But when a slight idle load (A/C) is introduced it goes down to about 13 inches and stays there.
7. This all started after a long pull up an on ramp, at about 5200 rpm there was a small pop and rattle then the intake got loud and exhaust note changed. The next 5 miles the car drove normal just loud, but after work driving home is when it had no power.

I believe it is either a partially plugged cat or it jumped timing, but the timing set only has about 20,000 miles on it, installed last week of december 07 and the cat and exhaust was replaced last week of Feb in 07 with maybe 26,000 miles on it.

Thanks for any help,
Josh

Sorry 2.4 auto with 143,000 miles.
2.3 tb and secret cams should be the only thing that would effect vacuum.

Sounds like a clogged cat, low intake vacuum and loss of power. Disconnect the cat and drive the car, see if the power returns.

Thanks man,

Ok, tried something. Pulled the front o2 out to let some pressure escape and it didn't seem to change it much, in fact while their seems to be quite a bit of exhaust coming out of the o2 bung most of it still comes out of the tailpipe at idle.

Any more ideas?

Lets say the cat will never clog again and its not the problem, someone has suggested to check the timing. Anyone think that maybe it?

what about the coil packs how old are they?

Jan 08, but they should be firing good.

Timing jumped a tooth, after a new tensioner and reassembly it ran fine but rattles from the the area of the timing chain housing and exhaust manifold, so looks like I am going back into it to try a new water pump. I just put one in, Dec 07, anyone else have one go that fast?

Bought my car last year and put a new one in about 2 months after purchase it was bad...Maybe its cause we raise hell with our cars, lol.