i have a 1.9 tdi a4 b5 and you can drive it fine but in 4th or 5th at about 3000rpm the turbo cuts out and goes in to limp mode but if you turn the ignition off then start it again it will go back to working fine with full boost until it cuts out again. please help with any info iv been told its the maf sensor but how true that is i dont know as there is 2 plugs that go to the maf it looks like someone has spliced into the loom and added another plug.