sorry if this was already said...at work....and in a hurry.
I have a 2010 with KO4 and have had my mani changed out 3 times under warranty. Its all about the dealership you are at. I found a great one and continue to go there.
One dealership replaced by manifold the first time, I popped the same code 2 weeks later because the manifold was faulty (the new one), then that same dealership blamed the turbo. I talked down to them and made them look stupid because that excuse was total bullshit. I went to another dealer and got it replaced under warranty the same day, in and out, without and appointment. That was about 2 years ago, they replaced it gain just a month ago and did a valve cleaning. I just paid the difference for the valve cleaning.
The manifold issue is purely design flaw. The sensor that goes bad can't be reached or replaced separately and it also goes bad because of carbon build up....another prob most manufactures didn't see with DI so it goes hand and hand. Thus the campaign.
When there is a campaingn and extension....etc.....the manufacture most defiinitely doesn't really have a solid fix and is just trying to keep owners happy until they upgrade to a new model.
Just try another dealer and be nice to them and break down the facts to them. They will find it hard to deny you if you come in there and be nice but also know what you are saying etc....not that you don't