I just purchased a 2010 Audi A5 Premium Plus Quattro Cabriolet with a 2.0T engine. I have not done any driving with it yet so it's been parked. I noticed when I plugged it up to the scanner I got a P0016 code crankshaft position/camshaft position sensor Bank 1 Sensor A, a P0303 Code Cylinder 3 Misfire, and a P0420 code Catalyst system Efficiency below Threshold Bank 1. I've changed the oil and filter, as well as the crankshaft position and camshaft sensor and I'm still getting these codes and the vehicle doesn't sound like it's in the best condition. Not to mention the fact that when I go to start it, it takes a few cranks to turn over. Is this a time chain issue I'm dealing with because I'm worried that I made a bad investment. Thank you very much in advance!