Hmm. Good info on how TIP works. I didn't log it, but I will now.
I live at 6300' in Lakewood, CO, but spend a lot of time going up and down the mountains over 10k'.
I thought the 2011 and 2012 F-150s had mechanical BOVs with electronic solenoid activation. There's also a 3rd solenoid for the wastegates. Regardless, the PCM has its hands in everything.
Any idea why the addition of a downpipe would make this so dramatic?