Haven’t been around in a while but dealing with a 2010 4.7L that I, nor any one else around here can figure out. It came as a severely neglected turd with number 7 cylinder dead miss fire. Rocker kicked off, knocked the keepers off the valve and KaBOOOM.

dismantle a 2011 4.7 truck with a minty motor but a nasty front end collision to steal the motor for the 2010. 2011 truck runs beautify, drove into the shop myself. Get motor swapped into the 2010 and I still can’t get it to run right. The trucks rich at idle especially warmed up but only idling under 1000rpm. Long term and short term fuel trims drop off a cliff to -20/-30 and lots of smoke from the exhaust. Truck still runs decent even at idle, just smokes and runs pig rich.

-O2 sensors and heaters are working properly
-fuel pressure is 62psi at the schraeder valve.
-smoke tested for vacuum leaks, none
-pcm changed
-fuel pump changed
-map sensor changed
-tipm changed
-purge solenoid changed
-throttle body changed
-ect sensor changed


I pulled the permanent codes from both trucks and neither have/had the p0172/p0175 codes for being rich on both banks. I really don’t know where to go from here. I have done many searches online to find any information and absolutely nothing I have tried has made any difference. Off idle, cruising down the road fuel trims come back to +/- 0% and the smoke clears up.