N62 issues after timing chain replacement

[raksike]

I have arranged the timing chain replacement on my X5 2004 which has the N62 4.4 engine.
I have ran the car previously for 2 years without the camshaft sensor unplugged, since this way it did run without any misfires or any rough idle. Probably the car has the worn Internediate levers issue.
Now after replacing the timing chains +many other things such as valve stem seals etc. the engine is running now rough at cold starts, the cam sensor is unplugged and after some time of driving I get in addition to the cam sensor error also the fault code P3019 which give the definition O2S Sensor Lambda Controller Value Above Threshold due to Open Pumping Current Circuit (Bank 2 Sensor 1)

When the engine warmes then it runs ok. Any suggestion where to start from now? Before the engine teardown there was no similar fault code, only the DTC for related to the unplugged cam sensor.