Once again we get someone "online knowledgeable" here that think they know it all just by reading forums. "Experts" like these are the reasons why we don't come back to forums much and let threads go dead for a while.
Poochie, let me give you a free lesson: O2 sensor Heater is activated from only few second (with Cold Start Enabled) to slightly under a minute (with Cold Start Disabled)
after the engine is started. During this time, the car runs in Open loop, with fueling supply closly based on predefined mapping with no Oxygen sensor feedback. As soon as O2 is heated up (takes only few seconds with the O2 heater element inside the o2 sensor), the car switches to closed loop and uses oxygen sensor for a feedback on fueling. This is CLEALY shown in a basic log of this M340i with Pre "O2 Heater Recall":
https://datazap.me/u/missiontuning/m...12&zoom=17-110
Look at the RPM vs Load vs Lambda vs FuelFactor. You see as RPMs rise past 4K, Load Falls, Lambda Falls and Fuel factor is NOT equal to 1? Lambda is an Input from the O2 sensor and Fuel Factor is a correction factor derived from the predicted vs actual lambda. See, even at full throttle, you still have Closed Loop Condition.
Now, please go back to the recall letter and read it fully. The recall is for the O2 Sensor Heater MONITORING function and not O2 Sensor heater or O2 Sensor Heater itself. The O2 heater
monitoring function has
Zero, Zip, Zilch, Nada relationship to functionality of the O2 sensor and function of the Open/Close. The O2 Heater Monitoring function just checks how many seconds it took for the car to warm up the O2 sensor to a minimum specified temperature....and this is why you can not set the OBD2 Emission Monitoring Readiness when the engine is hot. Every documentation you can read in paper or even online tells you specifically that to set Readiness, you have to start the vehicle COLD and let it idle for at least 20 seconds. During this time, o2 sensor heater
Monitoring function executes and checks the time it took for the heating element to get the sensor to the operating temperature....and according to that TSB, the function in question did not execute correctly.
Even with O2 sensor heater element RIPPED out of the sensor, the car will go into closed loop after at most 2 minutes of idle. Plain and simple.
PLEASE posts that entire article you just cropped and show us all where you pulled that info from? Back on ME7 (found on E39), that was true and ECU would disable the O2 feedback because of one little fact that you are missing: This holds true ONLY for Narrow Band sensors that can not physically output lambda value, but instead rely on lean-rich switching phase. Since Wide Band was introduced in later production E46 and EVERY vehicle after that, this obsolete 90s information holds zero merit on this topic. Just look at the log posted above and see for yourself.