E90/E91/E92/E93 (2006 - 2013)
My wife has been putting 87 octane In the car, And now it is running like crap. I put octane boost in and it's not seeming to do anything. I put a computer on it this morning and it's showing misfires on 1,3,5. Should I start with just replacing the spark plugs before I worrie about the coils...