Crank no start?

I swapped my engine out and ended up driving it around for about a month. And then I refilled my coolant and was in the process of bleeding it and then it started idling funky and once I shut it off it won't turn back on. I believe it's a fuel problem because I cannot hear my fuel pump priming or running when turning the ignition on or cranking the engine over. I did the five stomp method and it's giving me the code: (1222 - Oxygen (Lambda) Sensor Control 1) so I swapped my O2 sensor out and it is still popping up with that code and not starting.