Desperate help needed with open loop/closed loop fuelling

[scott3823]

HI All,
A couple of years ago I bought a 2011 DS3 with about 65K on the clock. It has given me lots of issues but it is getting there. When doing diagnostics on the car it shows it is running open loop fuelling permanently due to insufficient temperature. Now I'll go through the list pf parts I have recently changed (within months) so we know what to rule out:

• Walnut blast from Burch Motor Works in Christchurch (hugely recommended BTW for those of you south of Leicester and SP Tuning)
• New front and rear O2 sensors (Bosch)
• New Boost pressure sensor and MAP sensor
• New Thermostat Housing (most recent electrically controlled stat)
• New Valve cover/PCV
• Forge intake kit
• Oil catch can on turbo side
• GFB DV+ Diverter Valve

Now the coolant temp goes to normal (roughly 90 degrees) in good time, and whilst it sometimes drop whilst driving quickly it is fairly consistent. However it will not go out of open loop fuelling due to insufficient temperature. So, could some with access to diags tell me if this is normal or how quickly it normally switches to closed loop please? Also does anyone know if there are other temp sensors that the fuelling loop system will use that I haven't yet found?
I am inclined to believe that it stays in open loop because the front O2 sensor will sit at 0.8 volts and not fluctuate on idle so it is not reaching stochiometric at any point. A Citroen specialist thought this car should be a narrow band O2 but it is definitely wideband.
Any help hugely appreciated as this is driving me nuts!!!