2012 Mazda 3 2.0 Skyactive crank no start.

The car landed on my plate after being worked on previously somewhere else. The history is that the car died beside the road. The driver said it had run out of gas. Added gas and killed the battery trying to start it. Had new battery installed and still wouldn't start. Took it to a mechanic and had them work on it with it still not starting. Car sat for 8 months and then came to me. It has 4 codes. P2243, P0134,P0031,and P0101.
Will an O2 sensor circuit no activity detected cause a no start? I have a Torq Pro that I use for diagnosis. I got a fuel rail pressure reading of 1100 psi. I think the only thing that is causing the no start is no injector activity. The injectors are buried under the intake plenum , so I haven't been able to get an electrical reading off them. Any help would be greatly appreciated.

The O2 codes are probably a problem, but not *THE* problem. O2's, even widebands, have no influence on engine starting.

The P0101 might be worth a visual on the MAF itself. I've seen a few cases of a failed/contaminated MAF causing the PCM to reduce cranking injector pulse width enough to cause a no start. Unplug the sensor and see if the engine starts.

I know the injectors are buried, but you can still check spark at the coils. You can also pull a plug and check for excessive fuel fouling or contamination.

Will the engine fire on carb cleaner or propane? That's the quick and dirty way to see if it's just a fuel problem. If it is you can do your electrical tests on the injectors at the ECM

I had previously read about unplugging the MAF sensor. Didn't make a difference.

I did spray a little go juice into the air filter and it fired for a very short time. I will have to check the injectors for signal. My problem now is finding a wiring diagram. I am a part time maintenance man at a church, and the car belongs to a single mom.

You might have her pay for a day of Alldata subscription so that you can access the wiring diagrams you need. Having a wiring diagram is pretty much key these days in diagnosing anything.