Hi all Im having trouble with my a4 . The esp light is coming on and going off intermittently sometimes every 30mins some times every 5mins . I have scanned for codes and it either comes up with either p0101 pending or p0102 pending but never both . Ive trawled the web looking for a solution ive tried cleaning the maf with no joy and then replaced them maf with a new one with no joy checked for vacuum leaks and cant see anything . If i unplug the maf the car runs fine better than ever in fact . But if i erase the codes to switch the esp light off the engine will missfire at idle but run fine while driving . I am hoping its my N/S cat converter causing this as it has been rattling for a while and now it sounds that bad the thing may aswell as be dragging along the road . Can anyone tell me if this would cause this problem and codes to show? As i would have thought i would also get error codes relating to the cat converter aswell. Anyway im rambling now ! If anyone can help out its greatly appreciated .