This engine came with O2 sensors, and you connected them with the original harness? At this point, clean the connectors, disconnect the battery for half hour, then go from there, IMO.

 

Are these new O2 sensors installed when the engine was installed or originals? I've read here that many people have had problems with certain brands of O2 sensors.

If they are original, I'd check for vacuum leaks and monitor long term fuel trim which can be used to determine if you possibly have a vacuum leak.

 

Sensors did not come with the new engine, these are the downstream sensors.

 

Light kicked on and I could see at least one sensor bouncing between 0 and 1.3v. I have a single sensor coming in and will replace one of them to see if one code stops appearing.

 

Update:

I ordered a single O2 sensor to replace the driver side downstream sensor. Waited for the light to kick on and only a single code comes back for the passenger side O2 sensor. Ive ordered a second sensor and will replace it as well.

Just odd that they both kicked the bucket at the same time. If I have either die again I will update but it seems like 2 bad sensors.