Fellow mechs please help. My daughter just bought her first Audi, 2011 A4 2.0T. It ran fine for a month then stalled last week, check engine light on. I came to the rescue. Started fine, ran. Coded for a camshaft position sensor. I replaced it(I only found one) the next day. She made it about 45 miles and it misfired then stalled again. Same code. What's up with that? I recently changed the oil which was as black as I had ever seen in a car, and put new oem iridium plugs in. I used a generic synthetic oil. Is that ok? Car has a history of a front end collision. Any similar problems out there, or advice? Thanks in advance.