It will run learner with the ecu's lambada sensor in there, i took mine off and plugged my afr gauge in instead so that it would richen it so i could run more boost
Remember as its colder the fuel will be denser dont know if the ecu accounts for that tho also 3/4 on the temp gauge is high have you swapped the volvo temp sensor for the renault one? (not the one for the ecu the one on the flywheel side of the head). If not then it sounds like your car isnt warming up right until the end of your journey and on choke all the time.