D5 faults: 1600 Boost Pressure sensor, 1000 Atmospheric pr

[wooody]

Engine warning light on 2008 V50 D5.

Trying to get the car ready to sell and just had an amber engine warning light. Had been running low on power / sluggish for a little while. Scan using a generic code reader found a load of fault codes: 135F Mass Air Flow sensor, 18B0 Swirl Actuator Control, 500F Air condition, 6710 EGR control, 6720 EGR control, 2B00 Exhaust temperature, 1600 Boost Pressure sensor, 1000 Atmospheric pressure sensor.

Chased a few possible issues. Had the egr valve and throttle body off. Fairly coked up, so cleaned that all up along with the pipe to the inlet. No signs of damage to inlet pipes on top of engine, but haven't been underneath. Cleared codes, and seemed to sort some of the low power issues: felt much more perky.

But engine light came back after a short drive . Scanned again and had 1600 Boost Pressure sensor, 1000 Atmospheric pressure sensor.
Went back in and found swirl arm link was off, replaced that, cleared codes. Now running much better, back to full power (forgot how quick this was!).
But engine light back again and still get the 1600 Boost Pressure sensor, 1000 Atmospheric pressure sensor faults.

Checked live data on the code reader and atmospheric pressure at 994hPa (seems sensible), other sensor readings seem to move sensibly with throttle, but not sure what I'm looking for really. With the OBD function (rather than car specific) on the reader I get these faults: P2227 Barometric Pressure Circuit Range/Performance and P0069 Manifold Absolute Pressure Barometric Pressure Correlation.

Any ideas where to go from here? Thanks in advance!!