I replaced my air flow sensor, the idle is choppy, chokes, but when disconnected idles fine, is there a calibration step I need to apply ?
This is very strange, but I do believe this is common for a 7 series. Your best bet right now would be to uninstall the sensor and repeat everything again.
There might be some issues with the calibration as you pointed out but it's mostly human error causing this. Try again and let me know what happens :)