& thanks Joe....Will pit a keen eye on that!!

Is it easy to check, not been round back of engine yet?, & does this sound like something that would happen only when hot (soft) I guess??

Right, so last night I performed a smoke test by connecting to the intake tract towards turbo, through intercooler & back up into inlet manifold.........& nothing at all, no leaks to spot. Had a good look at intercooler which is not bowed, cracked or leaking any oil so i'm now totally stumped. The 2 red codes I had were;
ECM-44B0 Have replaced position sensor & cleaned out egr valve.
ECM-135F signal too high Have performed smoke test, no leaks.

What next please?????

Longhouse21 the following codes were all found but not active:-
BCM-0100
BCM-0115
BCM-0148
CEM-1A61
CEM-1A62
CEM-DF17 CAN-H
CEM-E000
ECM-1100
ECM-44A0
ECM-44B0 (ALSO FOUND AT FAULT?) EGR POSITION SENSOR
ECM-5730
ECM-6662
ECM-6663
ECM-6665
ECM-7700
ECM-E000
SUM-0336
TCM-0A31
TCM-E000

I guess if these were all to become active I should scrap it??
Still runs beautifully till hot??

The majority of the codes when I've done a search appear to come back as communication errors between modules or possible CAN errors.
One link I've found seems to point to possible issues with connectors on the wiring loom
( https://www.volvoforums.org.uk/showthread.php?t=266079 )
so may be something to look at?
First thing would be to clear the codes if none are showing as active then recheck if a fault occurs or just periodically to see what returns.

No mention of checking the swirl flap operation or position data.....

Also, the checks done on the new EGR position sensor to confirm that it works, were the same tests done on the old one to confirm that it definitely didn't work?

cheshired 5, I don't think the position sensor was ever tested, it just came up with a fault code by the independent garage? We put power across it & it moved the egr a bit but not fully & presumed it was duff.......the more I think about it the more I think the egr itself, although cleaned immaculately, is at fault here, & when it gets hot it gets stuck (the motor that is). Is there a way of testing egr if off the car???? I don't want to buy a new egr & find nothings changed....getting desperate now. Should I take to main stealer for more accurate diagnosis???? Anyone in Bracknell/Guildford have Vida????

Will do & thanks!!

longhouse 21, I've found more info(vehicle parameters)
ECM-AIR MASS 38.4KG/H
ECM-AIR MASS DESIRED 273.9MG/S
ECM-AIR MASS/STROKE 364.7MG/S
ECM-BOOST PREASSURE ACTUATOR,PWM 73.84%
ECM-INTAKE AIR TEMP (MAF) 29.86'C
ECM-EGR VALVE 100%
ECM-EGR VALVE POSITION SENSOR 0.88%

I think the last 2 are the key here!!!

So after countless sleepless nights I've bitten the bullet & ordered a new egr valve in the hope my hot running issues along with fault code of egr signal issue will be gone for good. My question now is will I have to have the adaptions reset for the new ege valve & indeed the new egr position sensor???