I've been chasing a rough idle for a wile now and I'm at a loss I've tried everything. To start, I rebuilt the 3.0 2 years ago and it has 70k miles on the rebuild. The entire engine was resealed at that time as well
it's been a rough idle from then on.
fast forward to now and I have no codes at all but when I check my 02 sensors they all read lean and the stumble verifies that.
What I've replaced:
spark plugs
Wires
Knock sensor
tps
Iac
Both temp sensors
Camshaft position sensor
Crankshaft position sensor
All 6 injectors
the fuel filter
Smoke tested the intake for vacuum leaks
Tested for fuel pressure all was about 50 psi at key on and 40-45psi running
coil pack
Maf
All 02 sensors
Pcv valve
ecm
I've checked system voltage for proper voltage and all was at 13.8-14.2v
No matter what i do the issue stays. I've tried everything except the fuel pump. The issue recently has gotten worse. Now if I start it when cold and throw it into gear it almost has a complete miss for 5 seconds then goes back to stumbling. In neutral at higher rpm 2000-2500rpm you can still feel a bit of the stumble.
it also has a bit of loss power till you keep your foot in it for a few seconds then it regains a lot more power. Anything will be appreciated as I'm at my wits end with this thing

 

Try cleaning the throttle body. The crank case vents go into it and it can get super gunky and this will affect the idle.

 

You didn't mention checking the fuel pressure regulator. That may need to be checked.