Last night the control engine light came on. 11PM, -3°C, 50km from home. Great - not. Drive home? Get towed?
So this adapter confirmed to me:
P0141 - O2 sensor heater circuit bank 1 sensor 2
= not critical = I could drive home without damaging the engine or catalytic converter
Last time I dealt with the exhaust system because of some lose/noisy part(s) I noticed that the connector of the 2nd O2 sensor (that just controls if output of catalytic converter is fine) did not latch (came off again by moderate pulling). So, most probably this is caused just by a bad connection easily fixed if there is a ramp, sunshine and +10°C instead of night and -3°C somewhere on the road.
Resetting the error flag to see if this was a one-time event did work as well.
So I can't recommend enough to get one of those adapters (better go for the Bluetooth version because of random Wifi connection problems with this specific adapter) to put in your cars toolbox.