Hello, I have a 2001 A6 4.2L. The car runs perfectly fine, however the check engine light is always on untill i erace the codes, but even then the light comes back on in only a few days. The codes have to do with the catalytic converters, both of them. However it doesnt seem like i need to change them any time soon. So if anyone could please tell me if there is a way of getting the check engine light to stop from coming back on? thank you!