[Brennan]

Guys have a bit of a problem with the car (318d 122bhp), a mate of mine plugged in his OBD diagnostics into my car and it threw up some error codes

44CC - Boost pressure Actuator - defective?
4521 - Boost Pressure Actuator - Regulation too high
4530 - Boost Pressure Actuator - Regulation too low
4B90 - Fuel rail pressure related?

Few things to note:

1) The car had a replacement turbo in January time
2) The car was remapped on the old turbo, supposed to be at around 160-170bhp
3) Car drives fine 90% of the time, occasionally will go into a reduced power state, performance is very flat and dead until 3000 revs, possibly this is limp mode?

I know even when the car appears to be driving fine, it isnt boosting to what it should be, as i have challenged a few friends in their 130/140bhp cars and i simply cannot catch them, especially accelerating from a standstill.

I have spoke to a few people about the problem/codes and they have suggested to check/replace vacuum pipes/hoses, clean EGR valve etc, although i have a feeling it probably is more serious than that.

Any info would be appreciated guys before i go mad, cut my losses and get rid of the car.