Pulled a p0172 on a 2002 F150 with a 5.4 with 210k miles.
Truck has been occasionally stumbling or rough idling, then clearing up over last two weeks.
Replaced plugs and coil packs about 15k miles ago, along with pcv valve and hose and it's been super smooth until now. Used aftermarket plug packs and motorcraft plugs.
Oxygen sensor values on bank1 are both .5 or above on sensor 1 and 2 and never really go lower, and bank 2 values change.
Idles smooth when cold, but gets rough as soon as engine heats up.
Trying to decide where to start... I replaced the heater core last winter... and after that much effort, I want to keep my truck. Any suggestions?