I've actually been involved in this with my car, someone in the past has removed the genuine t piece and replaced it with a washer jet 4mm t piece, but there is however a solid ally piece that has been placed in the vacuum hose with a 1mm hole inside, mine however is in the pipe from t piece to actuator which I now know is the wrong way around so this could be why the car isn't very quick ?!!, I'm connecting another boost gauge today and I'm going to do a before and after on what boost it runs as is and what it's like after I've swapped it round.