Management light keeps appearing

[phil1971]

Hello all.  I have just purchased a TT TDI 2009.  The management light appeared after a few miles drive.  The garage i purchased it from is trying to sort this issue but i would like some pointers if i may.  Mass air flow code appears on testers unit.

Light appeared. So sensor on the air intake was unplugged and put back on. Light was reset by tester.

Light reappeared. so Sensor was replaced with new unit.

Light reappeared.  so intake on egr valve was blocked.  ( looks like a new egr valve has been fitted recently) light reset.

Light reappeared after about 20-30 mins driving.

 Any ideas as to what this may be?

 

thanks.