I had continual o2 heater errors until I managed to recalibrate the heater circuit.

I started the car twice with the two replaced rear sensors unplugged. Got a handful of error codes. Plugged them back in, reset the codes, no more codes related to the o2 heaters after that.

Thanks for that clarification! It's good to know it's related to non oem sensors.
I've seen the exact same problem that someone else had but wasn't clear why the pending codes were there.
https://www.bimmerforums.com/forum/s...code-in-shadow
Just same pending codes for the exact same tbing, O2 sensors.
I might just get OEM sensors. My post cat sensors are not even the right ones. The guy who had the car before me installed the wrong sensors, the wires' length is shorter than it should be. They don't make it all the way to where they're supposed to clip. Dunno if it affects functionality at all. I feel like they're from a different bmw model.

Andrew those were the actual errors I take it, not just shadow?
What do you scan with?
INPA has a separate button to scan for "shadow" codes.
If you use Bmwscanner (pasoft) then the shadow errors are yellow, whole active errors are red

I use foxwell for scanning (or think diag).

I was getting actual errors but I suspect the same condition I was having could be giving you the ghost errors. It's easy to try and if it works, may help somebody else down the road.

Does the engine have to actually be "running" twice, or can a simple key on suffice in order to "recalibrate" the O2s?

O2 sensor connections
 

I don't know. I started it I don't think I drove I just wanted to make sure the car tried to heat the O2.

The O2 heater circuit is energised at key on this I know because that's where I power my angel eyes

The actual power to the heater is controlled from the ground side

Andrew I tried testing what you suggested
Right now I have 2 shadow codes for pre cat sensors and one code for post cat sensors (2 up and 1 down)
https://i.ibb.co/hdJXts0/20211007-090735.jpg
I tried disconnecting the front sensor and running the engine.
I got this new error
https://i.ibb.co/mCLKm6Y/20211007-090444.jpg
I reconnected the sensor and tried clearing the errors. Error 25 Lambda cleared fine, but the shadow errors stayed.
I could try changing O2 sensors to OEM (even used ones) to see if anything changes.

Photos too low res to read. Are the shadow errors twisted to the heater ckt? That's what I suggest can be fixed with the recalibrate from running with them unplugged

Those are thumbnails, will open in full resolution if you click on them. I think they won't open properly if you use tapatalk.
I'm not sure what exactly those errors mean
I can rescan with bwmscsnner
I wish I had some extra O2 sensors to test it by replacing them

Ah yes I use tapatalk


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