all great tricks till you try to do the piston soak on a fricken boxer engine in Subaru.. OOOMMGG.. LOL..
could you at oil change put a bottle of B-12 in crankcase and run at high idle for 10 mins or so with hot engine.. the change oil using Restore and protect?? have a daughter out in Fort Collins with subaru 2016 forester with 100K.. going to suggest Restore and protect ONLY in crankcase for oil changes..
PS if anyone knows of an oil change place that will put in oil you bring in Ft Collins area let me know..