My 2008 a4 2.0t quatro keeps telling me that I need to close my fuel tank cap. It is closed and I have replaced the cap and also replaced the purge valve as well. Any suggestions on what might be causing this issue would be highly appreciated

 

I had that issue and it was the n80 valve (or purge valve) that cured it. I would guess there is a leak in the system somewhere else. Not sure if it would be between the filler and the tank or anywhere up to the engine. Maybe someone else will have more insight.

 

I am now having the same issue. I also have a check engine light on too. I drove Down to ocean city Maryland and back. The next morning this was happening... Did you guys find a solution? Also, if you don't mind me asking. How much was the n80 replacement?