Do you have a MINI diag book to look up the codes? I don't have mine handy at the moment, but that book would be very helpful to you. I think 5E5C is something related to traction/stability control.
https://www.pelicanparts.com/MINI/catalog/shopcart/BOOK/POR_BOOK_minibk_pg2.htm is the book.
P0326 thread:
http://forums.pelicanparts.com/mini-discussion-forum/930552-knock-sensor-issue-r53-mini.html
I definitely think you have multiple issues a-foot.