A6 computer
 

Looking for some advice. I have a 99 A6, Quattro 50k. After a moderate real end knock the check engin light came on. Dx main computer failure, one o2 sensor out and one on the way out. I was told this is common and rear end bumb unrealted. Does this make sense? I am surprised to have a computer failure at 50k. have to keep the thing running. My yellow lab loves it.
TIA