Hello all,
I'm new to the forum and have been looking this issue up as I know its been talked about an awful lot and quite recently too. After changing parts and sensors after reading everything I have seen I'm still having problems with my GTIs boost. Originally the issue began when the car had zero boost 24/7 no matter how it was driven and then suddenly one day on my way to my local VAG specialist the boost kicked in throwing me back into my seat which was a pleasant surprise. Its worth noting the previous owner had got someone to put a stage 1 map on it. when the car was at the garage I had the PCV and high pressure fuel pump cam follower replaced along with some other non boost related work
. After this the boost issue remained the same so I then went back again and got the Diverter Valve replaced. The boost then weirdly would only work on the first start up of the day and then if the car was parked up and left for roughly 30 minutes then started back up the boost wouldn't work? this then lead me to believe it must be a faulty sensor so I replaced the MAF sensor and Boost pressure sensor this changed the cars behaviour so now the boost doesn't work when under full load but if I only use half the throttle or less I can feel the boost working? I got the car hooked up to VCDS and Ill put the information displayed in the fault codes below as it says the car is in a over boost condition. I'm taking the car back to the VAG specialist again soon to take a look at the N249 & N75 valves to try get this car sorted. Could it be a dodgy map with too much boost pressure considering the car was mapped while in this state by the previous owner? (I've not owned the car long) any help or guidance would be greatly appreciated. Fault codes below
Thanks in advance
"Manifold pressure / boost sensor (G31): Implausible signal P0236 - 008 - Implausible Signal"
"Boost pressure regulation: exceeded (over boost condition) P0234 - 001 - Upper limit exceeded"
