Hey everyone,
I am an A4 B5 owner marooned in the inland northwest with no Audi dealers or shops any where within 100 miles. I ran out of gas this morning(while charging the battery on my GF's car) and let it sit all day while I was in class. Upon returning home I hoped on my bike and went to the gas station. After returning, adding fuel and starting my car(a very rough and jumpy start, which I attribute to empty fuel lines) the check engine light came on. I first tried to tighten the gas cap(to no avail), start without the cap in place(worthless) and re apply the cap(nothing). If you know anyhting about why this happened please let me know. Luckily I have my bike to get me around but if it rains I'm not going anywhere! Thanks.

 

I am sure if the codes were scanned, misfire codes would come up which would relate to your rough start situation. A variety of things would make this happen. My initial response would be the fact that you completely ran out of gas caused the system to lose pressure and upon putting new gas into your tank, caused of that pressure to regain. However, with that gap in pressure still in the vehicles system caused it to stutter and misfire. If it does not continue to happen, I would not be concerned.

 

It may be ignition-related codes from the car stalling out and then trying to restart before the lines are filled.