Possible boost leak

[Peaky1]

Hi all the car is a A4 b6 1.9tdi 130bhp Avf quattro. I've replaced all egr and turbo vacuum hoses. Replaced the N75 valve. Had the turbo rebuilt, replaced hose off the bottom of the turbo. Took it for a few runs pulls a lot better but it doesn't feel 100%. Doesn't want to spin the wheels in 1st gear either. When on the the motorway around 80/90 the eml on with P0234 code. I'm still getting what sounds like a blow off valve which I thought before having the turbo rebuilt was the the turbine hitting the housing. The egr is blowing oil out the 2 holes at the top. I've ordered a new egr valve plus a new non return valve. Any help would be appreciated. Thanks

[Crasher]

P0234 is overboost, are you sure it isn’t P0235?

[Peaky1]

100% p0234

[Crasher]

You don’t have a leak then, in my experience that vast majority of overboost codes are a fault inside the turbo, very occasionally I have seen the MAP sensor over read and even stick at 2880mBar. You need to do a boost graph in measuring blocks 011 with requested and actual boost displayed.

[Peaky1]

How would you explain the turbo whoosh when letting off the revs. Also the off the the mark pull in 1st being low in power. Do you think there could be a build up of oil in the pipe bend just off the intercooler that could be caking the map sensor?

[Crasher]

The noise from the turbo is a characteristic of a problem with the VNT mechanism, I would describe it as a chattering breath that needs a shot of Ventolin.