Recently my wife's 2006 A4 2.0T Quattro had the check engine light come on. Ran the code and it was for P0011. The car ran fine and always has. Light comes on and off sporadically. Sometimes its on for days, then off for days, but always runs fine. Went through inspection last week. The car failed for 2 codes P0011 and P2181. I googled both codes and still not sure what to do. Any help would be great. Timing belt was done 2 years ago just fyi