(2001 TT 225 Quattro). My check engine light has come on (steady, not flashing) and I have taken it to the Audi dealer for service. The code that keeps coming up is "secondary air-incorrect flow". They reset it saying it was a sporadic fault and within a couple of days the check engine light came back on. Same code. They replaced a "split vaccuum line" and reset. In another day or so the check engine light came back on. Same code. They replaced a "valve" of some sort and reset. A day later the check engine light came back on again (always steady, not flashing). Any ideas or recommendations as to a well qualified TT diagnostic technician would be appreciated.(I live in Maryland).