I have been able to manage a little over 30mpg out of my A4 LS1 when driving on the highway. But now all of the sudden, my mileage has dropped. I checked it last week and I was only in the low 20's! What could be causing this much of a decrease? I have actually noticed that the car smells like it is running rich. What should I check into?

 

You may want to reset the computer.
http://www.ls1info.com/article.php?sid=197