If ALT was bad enough to cause a power issue when you turned it off it wouldnt of cranked back
If fuel filter was bad the problem would still be there after you restarted the car
If O2 sensor was bad you would get a O2 CEL and after 4-6 min would fail to closed loop and run good again , I like the advance and bosch o2 sensors and have used hundreds of them with maybe 3-4 bad ones but they have a years warranty (think ford does to) and easy to replace
My guess is the VCT either sticking or going bad , unplug the VCT solenoid and do a very short drive (50-100 feet will tell you) and see if it feels the same loss of power , when unplugged you will loose about 30-40HP right off the bad
I am not trying to shoot any ones ideas down when trying to help just running them through my mind and trying to save him time and money from changing a lot of things out
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