what to do next on 2003 Audi A6 Quattro

my check engine light came on and I was told by a service machinic that it has to do with the cat not warmming up what do I need to do next.

Asked by for the 2003 Audi A6 Quattro
Which engine? I don't think the 2003 models came with heated cats. Are you sure it was not the O2 sensor heating or cat. converter efficiency code? Do you have the exact code?