I just dug out my service records, my AOS was replaced 11,000 miles and around 18 months ago. So I am going to try the MAF first since that has been longer.
I also have on the schedule to replace my spark plugs, and spark plug tubes and O-rings as they are weeping a little bit of oil, and so maybe this oil is somehow smoking.
MAF is easier to replace than AOS anyway
Steve