CDTI 150 P2147 P2150 random stalling

[MrF]

Hi guys
Any idea what would cause a CDTI 150 estate to stall out randomly? (my dads car....tempremental thing...)
Happens at seemingly random intervals, in town, on the motorway etc/ Won't bump start (i.e. dropping the clutch) but will start up no problem if you turn key off and back to start.
Throws P2150 and P2147 errors, with occassional P0268 error
At times also flashes up water in fuel errors on screen but doesn't log a code...

Had previous DPF errors(wouldn't rev out, sensor errors) some severe italian tuning seemed to have sorted that, EGR and MAP sensor both thoroughly cleaned recently. Possible DPF involvement?

Has been done thus far:
all injector wiring plugs replaced
Spill off pipes between injectors replaced
Diesel filter replaced
Battery left disconnected for a while (the old turn it off and back on theory)

Any ideas what to look at next?

Had an ECM software upgrade a few weeks back to improve the DPF regens, dealership botch the update perhaps?

Any help GREATLY appreciated before I lose my mind completely.....

[mally]

My guess is a boost leak, more than likely leaking through the egr valve, creating more smoke thus filling the dpf quicker.
Suggest replacing the egr valve and dpf if it's to far gone to regen itself, or more sensibly, full blank egr valve and have the dpf emptied then remap to suit.

[MrF]

doesn't really smoke, pulls like a train so doesn't feel like a boost leak,
DPF was seemingly changed by last owner in april though whether thats true or not is another question (wouldn't put it past a garage to forge an invoice for a mate...)
Going to check down the front of the engine / underneath for an exhaust leak as there is what looks like an ocassional puff of exhaust emissions from below the turbo (not sure if exhaust fitted properly (new exhaust fitted just before it was bought)
DPF saturation levels seem alright...and a manual regen succeeded but previously didn't clear the DPF...albeit revving the guts out of it got it to clear...
Might try blanking the EGR next (albeit not throwing a code, which it did when it was first bought...no wonder...it was manky...)

Frustrating as its intermittent and can't replicate the fault, someone reckoned it could be damage to the wiring harness...but seems too random to be that...

[mally]

Well it won't smoke as it has a dpf fitted.
If you're taking the egr valve off try gently running water into the rectangular side. If it comes out of the oval side, it's broken and no amount of cleaning will bring it back to life.