The car starts but won't idle when cold and will continue to stall until the engine warms up (approx 5 min). Once it's warm it idles and drives fine. If you try to drive the car whilst the engine is cold and you are not required to operate clutch & brake pedal at the same time the car will drive fine but as soon as you stop riding the accelerator the engine stalls immediately .

At first it would stall only for a few seconds when cold and it's gotten progressively worse.

Note we have had to perform 2 forced DPF regens this year.

I've tried to evaluate data, temp sensor values seem to correspond with temp of engine, actual fuel pressures seem to meet desired values.

Peter Arnold - My first thought was does it have a similar problem to the YD25 engine in Nissan Navara where timing chains stretch and causes stalling when cold. Disconnection of cam sensor would indicate timing chain problem if engine didn't stall after disconnection.