04 F150 5.4 261k miles
Error Codes- P0171, P0174, P2197, P2195
Codes are related to the system stuck lean in both banks
My f150 has been idling rough and stalling when coming to a stop when stopped, or put in neutral. Have to have MAX AC going to keep strain on the engine- it works 70% of the time when sitting at short stops...anything longer and it will stall out. You can smell the exsuasut...smells like glue or maybe "rich" emissions ( I don't know how to describe lean vs rich) it just smells like heavy exsuast.

My guess was 02 censors... I've changed two before the cats ( 1 per side) I have yet to change the ones before the cats.

Upon closer examination I've found vacuum lines (very small ones) disconnected everywhere including a boot that looks like it comes from the back of the intake manifold. They go to the 4x4 hubs I think. There's a valve on the passenger side they run into and a 4x4 box with brake lines in it on the driver side under the power steering reservor. Those are now suspect.
My gueses:
Bad 02 censors
Vacuum Leak
TB dirty




Line disconnected by valve on passenger side



Valve On passenger side



4x4 Box with brake lines under power steering resivor



Line disconnected on driver side by 4x4 box

 

O2's are not likely bad. Most likely vacuum leaks.

 

I believe those lines are for the WEI valve. The other one are for the vacuum relieve for the 4x4 actuators which are bent or curved pointing downwards. Nothing of those hose will make your truck run like you say. I'm here because my truck has been down for almost a year now with same symptoms and can't figure it out yet.
Mine now throws black smoke when I try to take off.

 

All 4 codes are set because there is a vacuum leak into the intake tract from some source.
The Ox sensors detect this condition. They are not the cause.
The detection results in the computer shifting the long term fuel trim tables rich trying to account for the access air.
When the tables shift 25%, the codes are generated and CEL turned on.
The fuel tables shifted result in hot idle and low speed stalling.
Cold starts will seem ok until the engine heats up.
Find the vacuum leak.
Good luck.

 

I bet that since this is an 04 it is probably the skinny vacuum line going into the back of the intake on the passenger side of the manifold that is causing the problem...