Was there a code? Never seen such a message before...

Sounds like the tool fails to cope with the front O2s. Note: they are not voltage-based (I don't see what actual MY etc this car is, however).

 

This was a message for why the car won't go into readiness. Says low temp. Can't be coolant temp, as it's reading fine via OBD

The car is a 2004. That would explain why I don't see voltage in the PID for the front O2s then. The tool might not be able to read them for sure. I just have a hard time believing that both front O2 heaters went at once.

 

Here is the readiness guide for the o2 sensors.



Here is what triggers a P1646 and P1647.


If you need some of that additional info, I can track it down. I hope this helps.

 

Thanks! I actually did not do the O2 drive cycle. I did do the one that's supposed to get all of the readiness tests, though. It only succeeded in setting the Misfire and one other that I can't recall at the moment.

I'll post another update soon...