1.8T turbo troubles help needed 5 psi only!

[M1K3Y--B01]

recently bought a 1.8t golf gti had no problems until last tuesday, took it for a spin everything seemed normal until i put my foot down turbo seems hesitant and will not go above 5psi its very laggy! iv checked maf sensor and coil packs but changes nothing hoses all seem fine turbo is mechanically sound so i beleive its electrical but i cant get vag com working either. anyone had a similar problem or know what to do? any help would be brilliant cheers

[PishY]

Check the N75 valve, the plug and hoses going to that,

had a similar problem and was the electrical cables had perished.

its near the intake pipe, sits onto / next to it.

[M1K3Y--B01]

from what i can see n75 valve is all connected properly cheers anyway

[MaXXeH]

sounds like the car is in limp mode.  you need to check it for errors

[M1K3Y--B01]

ran a diagnostics on it and found the map/thrust sensor was faulty i have replaced it and it seemed as tho it had fixed it until i really pushed it.. now it seems to boost up to more than it ever has done gets to 20something psi and then spits lags and coughs :S very confused very worried any help would be appreciated

[topher]

Sounds like a fuelling issue, or a cheap aftermarket map sensor. Avoid driving it hard until you get it sorted. You don't want to be underfuelling when working the engine, byebye pistons!