Hopefully somebody may have some advice for me. 1999 galaxy 1.9tdi. I bought the car 6 months ago with various issues for £400. Have had the issues fixed except the P1550 code, control deviation - intermittent. I've spent a lot of time researching this and found it could be the following; N75 valve faulty Vac hose from turbo, n75, n18, brake servo I spent some time time changing all vac hoses over the weekend, with the last hose being changed the one on the actuator. This had rubbed considerably against then chassis/bulk head and worn a hole! Bingo!! Swapped the hose over, and all was fixed. The car went like a rocket n the turbo spooled up nicely, the lumpy idle went and the brake pedal no longer went hard on rare occasions. My first outing today was for a 200 mile trip so I thought an ideal time to test run it. All worked perfectly until sitting in traffic n the m25, the engine light came on. What next?! Strangely, the car only suffered from a lumpy idle. The turbo till spooled up, albeit not as well as before, and there was only a marginal loss of power. Once home, I ran vagcom on my laptop and the same fault code came up. Is it likely that the n75 has failed? Would this result in the car not running well but not going into limp mode? I've checked my newly fitted vac pipes and they are all still in place. The only thing I've not changed is the n75. I'm happy to get another n75 but would appreciate anyone's advice! Thanks for reading.