there's a reason your AFV value is all over the map. ask the ecm gurus why. i'm not one of them.
O2 sensor on the way to death row.
pull your front spark plug and check. betting it's slightly fuel-soaked and sooty black in color. that will confirm overly "rich" mixture.
check for historical fault codes....see list below. betting #13 is revealed.
vacuum ports have no "interface" whatsoever with the fuel system and/or an injector. to clean an injector it would have to either see a cleaning agent thru the fuel delivery side or be removed and physically cleaned.
your tps unit might be dying. my check suggestion above will reveal.
11 Throttle position sensor
13 Oxygen sensor
14 Engine temperature sensor
15 Intake air temperature sensor
16 Battery voltage
21 Interactive muffler control (XB12 only)
23 Front fuell injector
24 Front ignition coil
25 Rear ignition coil
32 Rear fuell injector
33 Fuel pump
35 Tachometer
36 Cooling fan
44 Bank angle sensor
52, 53, 54, 55 ECM failure
56 Cam sync failure