Engine Service required keeps showing on DIMS

[Tee5alive]

Hi folks

well my engine STILL isnt happy. I kept getting the dreaded 'Engine Service Needed' which usually precludes being left beside the road with a dead car or trying to get home in 'wimp mode'

2004 V70 D5 automatic btw.

I have three codes on the OBD2
P0401 EGR 'A' flow insufficient detected
P0244 Generic Turbocharger/ supercharger wastegate actuator 'A' range/ performance
P0571 Generic Brake 'A' circuit

Now the first one CANT be correct as I have removed the EGR and it was indeed like the bottom of a Yorkshire colliery blocked pretty much solid so I have adressed that and cleaned it out thoroughly and performance improved (for a while)

Ive not actually HAD limp mode yet but she is lacking performance and accleration when you need it (as in trying to pull out before a foreign trucker tries to flatten you)

The Brake switch I know will not affect performance my dealings with this switch on past cars - it prevents CRUISE from engaging and cruis is FINE so thats clearly another spurious fault

My main suspicion is the 'wastegate actuator'.

Currently I am mainly reuilding the turbo I have had to remove from my other T5 (a VW TRANSPORTER!) which had a seized VNT nozzle ring again due to carbon concretion! The fault looks strangely like this but the V70 has a 'proper' wastegate not these awful VNT things (which jam frequently on diesels)

Ive replaced the turbo on a previous V70 but that was clearly a blown turbo ( the turbine had seized).

So over to you knowlegdable experts please what am i looking at replacing to stop this 'Engine blah blah' every 10 seconds annoying me driving to work and keeping my car running as she used to like a Swiss watch? I truly adore this car and it cost me a lot more than my past ones so I want to look after her. She was a 'low mileage' (120k running in milegage for a V70) one disabled lady owner before and she FEELS new apart from this - the car NOT the lady!!

So can i pick your brains please and HOW can I clear the 2 faults from the CAN that I pretty much KNOW are errors and pure 'ghost faults'?

Many Thanks

PS what does this 'A' mean against a fault???

could it need the DPF celaning out with that chemical? Just seen a guy on here do it and his fault cleared?