I replaced the PCV vacuum line today (the short 2" piece that connects the PCV to the intake manifold).
I didn't replace the PCV oil separator tube, that turned out not to be the problem.
The vacuum line I replaced was split. After I replaced it, long term fuel trims went down to around 6%--not perfect but a lot better than 25%.
I also discovered that I knocked the IMRC return spring off of it's catch, so it gave me an IMRC code. Re-installing that was fun.
I still have a slightly unsteady idle, but I think that's because I made the mistake of cleaning the IAC valve.
No big deal. Advance Auto has a replacement for $30.
