Audi A6 emission control light has come on - what does it mean?

I have an intermittent fault with my Audi A6. The Emission Control light comes on and goes off randomly. It all started in October where I had to do a lot of short journeys. But most recently the light came on after a 130 miles round journey. Any ideas?

Asked on 16 December 2014 by VJ09

Answered by Honest John
The DPF is clogged with soot or ash. A long drive of 200 miles or so might prompt it to actively regenerate and clean itself up. But if it is clogged with ash it needs professionally cleaning by the Ceramex process (£300) or replacing (about £1000).
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