irasend

So after much trial and error, the noise seems to be coming from the knuckle at the attachment to the lateral arm.  How common/difficult is it to change out that knuckle bushing? Is it available after-market or do I need to get one from Subaru? In my diagram it is called the rear axle housing bushing.

My 2015 Legacy 3.6R recently developed a nasty creaking noise coming from the left rear wheel.  Happens with any up and down movement of the left rear wheel eg. getting in or out of the car. any uneven road etc. Got underneath and sounded like it was coming from the lateral link. Changed the bushing without improvement. Any thoughts?

"Check oil level" warning light coming on in my 2015 Legacy 3,6R recently, despite full oil level. Have 105000 miles on car. Service manual says "to test switch insert the spare fuse in the delivery mode slot".  Does that mean to remove the fuse from the BACKUP slot and put it in the delivery mode slot, ie. put the car in delivery mode, or to just take an extra 30 amp fuse and insert it in the delivery mode slot?