Originally Posted by
pioneer4x4
At time 377.2, notice how both bank 1 O2 sensors go to 0V, you might have a ground issue, or a short to ground issue. Just a guess, but I have seen an engine harness rub through and cause issues only under full access when it rubbed a certain way, but looked fine under the hood parked.
A weird ground issue may also explain the other sensor going weird. But as you mentioned Bluetooth OBD2 isn't perfect either.
Ok, this is hard to make sense of.
Go look at the diagram in the service manual. Then read this:
How Does The Oxygen Sensor Work? - Technical Information - NGK Spark Plugs Australia
With one kind of sensor (Zirconia) , an open ground will cause the PTCM to see zero volts because such sensors develop their own voltage.
But a Titania sensor is biased by the PTCM, so an open ground THEN would cause the PTCM to see 5 volts, not 0 volts.
Without knowing which type we have.... I'm lost here. All you can do it inspect wiring to see if, indeed, you have an open ground. With BOTH doing the same thing at the same time, it sounds like we have Zirconia sensors and that the ground connection is opening up. That is the only way I can see BOTH showing 0 volts at the same time.
Of course, my other idea is that the PTCM is just plain bad or confused - but I don't see a bad PTCM also capable of making the car "run like new"...