Hi - I have 01 plate galaxy 1.9 TDI (115bhp) - It drives fine up to 45ish mph and then foot to the ground, it struggles to get above 70mph. I was adivce to replace the maf sensor - this has been replaced but same problem. I have tried disconnecting the maf sensor and notice a differance in performace and mpg was lot worst - i assume this proves the maf sensor is working. any ideas what i shoud try next? Thanks in advance