Just got the dreaded P0171 yesterday. Taking it into the dealer tomorrow to have them check it out. This would be valve cover replacement #2, if that's the case. 121,000 now miles and I think the first one was replaced between 50-60K. When I bought this car I set up a spread sheet to log any and all work done, but I got lazy after the third oil change and never kept up with it. I wish I had.
I'm also getting a P015B code. First time for that one.
Anyway, all repairs for my car are out of pocket now. I hope this doesn't cost too much.
Follow up edit: The codes were due to a faulty PCV (didn't ask for details) and it was repaired under warranty, due to the dealership making this repair before. However, the service manager told me it was covered under their 12 months/12,000 repair warranty, which I was WAY past. I think he felt bad for me due to how many times he's seen my car in for repairs over the past three years and just wrote it off as a warranty repair.
Car is still in the shop though due to a creaky steering wheel (something in the column is making noise) and some front left suspension noise. Not looking forward to the cost of those repairs.