[Gezzaxc70]

Hello to the Volvo community. I have a 2006 XC70, 96,000miles full Volvo service history, owned for a year of perfect driving. A month ago whilst driving on M4 to Wales the engine system service light & triangle appeared but ran ok. On way back from Wales, also on steady motorway cruising the cars message changed to soot filter full & went into limp mode.
Following day took to independent who diagnosed faulty DPF temp sensor & confirmed the soot content was within normal parameters.
Car then worked for 2 days (50miles) & to my horror the engine system message re-appeared closely followed by limp mode but no soot filter message. Took back to independent who said its now poss the egr valve & recommended changing the egr position sensor.
This time myself & a technician from work removed & cleaned entire egr assembly (now shiny & new) & wasn't too sooty, tested egr function & fitted new egr position sensor.
Unfortunately after driving for 5-10mins (this happens everytime) the car reaches running temperature & goes into limp mode. Plugged into Snapon diagnostics which showed egr working & the fault of MAF showed up again as always. Was told by indy that this is normal when "something in the intake system is wrong". Took off & blew MAF assembly to no avail.

Now desperate I come to you experts for guidance on weather this is the cause of a common problem elsewhere like a leaky pipe or such like.
Sorry for long thread but like to be thorough, many thanks Gez.