sorry about your issues with the this car. I has a 1999 328 up until last year. I am not the most mechanically inclined person myself but I had a code for my secondary air pump on my which was a 100 replacement cost. As far as the oil burning and smell I would take a guess that it sounds more like it could be the valve cover gaskets are leaking on to the exhaust manifold keep an eye on the oil level in the car. Maybe some one else on this or other more active forums might be able to help you with your issue.