I have a problem with my mk5 gti bwa it has low boost and is only boosting 5psi and only revs to 6k rpm I chaged the turbo dv valve and n75 made no difrance I tuck car to a garage checked all fuse and there fine the garage said maybe could be timing or injectors so instead of just hoping money at anything I just bought a full complete engine the only thing I used of old engine was harness and the car is still doing same think as old engine would a faulty engine harness cause this problem the car runs good and drives itdose not misfire or anything it dose boost a little bit but nothing what it should I am just running out of options now the only thing that has not been changed is engine harness and there is no fault codes with vcds please help
