Blue smoke coming from tail pipe

It sounds like it is either overfilled with oil or the air/oil separator (item 24) mounted on the block has a problem. It does the job of a PCV valve and is supposed to keep the oil from getting into the intake system.

First check the oil level. If it is high drain it and refill with the correct amount.
Next the system would need to be dismantled and cleaned out to remove the oil.
The air/oil separator would be replaced and all sensors cleaned of oil or replaced depending on how they test.

The CEL flashing is due to misfiring cylinders, you do not want to drive the vehicle like that as it will damage the catalytic converters even worse, although the burning oil may have already poisoned them.

Oil on/in the sensors will make them act odd and that can cause other problems. Like drive ability and engine power loss.
The cleaning is the first step. Then you need to use a scan tool to read the stored codes.
That all gets you to a starting point where you can begin diagnostics.

That could be the heat shield(s) on one of them. Get things cleaned up and test for the codes. I have seen converters take a lot of abuse, they just do not like it for long terms.