acceleration problem

[BauerExplorer]

sometimes when i press the gas, a little or a lot, the rpms actually go down and the truck doesnt accelerate. if i continue to do that i hear a bang noise and the truck shuts off. any one know anything. it started doing this the day i got my truck back from getting the passenger side 02 sensor changed.

 

[aldive]

Is this event triggering a CEL?

 

[BauerExplorer]

its on for an o2 sensor but all of them have been changed, i have a rough cold start but i think thats because of a vacuum link, im thinking of taking it to ford this week but dont really want to spend the money there.