Had no power, hard start, would bog down

Have a 2002 astro van had no power, hard start, would bog down when you pressed on gas cold or hot. Does this sound fuel related or an issue with O2 s

Have replace MAF sensor, coil, plugs, wires, CTS, starter, crank sensor, fuel filter, cap and rotor seems just about all had failed. Had multiple codes before but now only have code PO300 Van now starts right up, Idles rough for about 1min an then smooths out until you step on gas above 1300 rpm then wants to bog down again checked the graph on the O2 bank 1 sensor 2

(there are three on the van) and it showed 0.1 to 0.8 V for two min then dropped to 0.2 V and was until 4 min in and it went to a reading at about 0.7 V and remained there until I tried to give it gas at which point it dropped to 0.1 an then back to 0.7 until shut down.