Ihave a 2000 a4 quarto 1.8t wagon. Does anyone have info on what would cause my car to spudder almost as if it was loosing fuel. Gonna try cleaning or replacing the fuel filter. Any additional info please. Also has anyone experienced loosing oil with no visible oil leaks and no signs of burning oil. last thing can the catalytic converter be replaced with a straight pipe with out causing damage to the engine or turbo? Any help is greatly appreciated.