Just purchased a 2007 A4 last Nov. Had 70k miles on it so thought that any significant issues would have been worked out. After about a month the CEL came on. As my OBDII reader would not work for some reason, I decided to buy the vag-com from Ross-Tech since I do a lot of DIY. Found that the codes were the 442 and 455. Reset the codes and came back about a week later. Forums indicated that it could be the N80 valve or fuel cap. Did not see anything specifically wrong with fuel cap, but decided to buy one anyway. Also bought the N80 since it was not very expensive. Since Dec, the codes have come up about 6 times. Decided to replace the N80 today...those crappy hose clamps are a pain, but snipped them off and had the valve on in about 20min. The old one was definitely bad. Had a significant leak through it both directions whereas the new one had no airflow. So, we will see if the N80 fixes the codes. I feel that the 442 should be fixed, but not so sure about the 455...possibly. Also had to replace a coil pack a couple of weeks ago. Definitely will not make long roadtrips with the laptop and vag-com. My opinion, it is worth the money if you do a lot of DIY, but do your research before getting too brave with that thing...looks like you could really screw things up quickly!

 

Resetting codes does not fix anything. The car sees a problem , that is why the light is on & will continue to come back on until the problem is fixed.
More than likely the n80 valve is bad. Audi dealer probably has a shelf full of them. Pull it off , suck on the vacuum side & see if it holds vacuum. If it does not it is bad.

 

4 days and no CEL. The car even started with no problems after filling up. Hopefully the N80 valve took care of the problem.

 

Well, 2 weeks and no CEL....definitely must have been the N80 valve.

 

I'm very new to my 2007 Audi A4 2.0T, as well as general DIY items. I already have to replace the purge valve, and I would greatly appreciate any insight as to where to find it. Any pictures would also be insanely helpful. I just can't seem to find anything else online specific to my model.

On another note, is it better to just reply to an old thread like this? Or would it have been better to start a new one? Once again, I'm a newbie.