Hi all,
I was driving along, and suddenly, the engine stopped. No weird bumps, or noises, no seize, just stopped running.

I had recently smelled fuel near the car, I thought it was escaping via the gas cap, it's been pretty hot here in AZ.
I replaced the O2 sensor. But I have these engine codes:

511
512
231
122

I am especially stumped by 511 and 512; 231 is why I changed the O2 sensor.

Any advice?
Thanks