Just did an engine swap and put in a low mileage 4.6L engine out of a 99 Expy and now I am chasing a misfire. The first problem I had was a code for the #5 injector which I replaced. Now my problem is that it seems to run very rich on startup, evidenced by white smoke from the tail pipe when revving it, but at the same time runs smooth and seemingly without misfire. Once it warms up fully though it has a pronounced miss.

I have been researching for several days and I have read about vacuum leaks, and egr, and etc. I was hoping that someone would be able to point me in a direction given the fact that it does not miss until it warms up. Any help is appreciated. Scanner results below.

Brand: Ford
Model: Expedition
Year: 2003
Displacement: 4.6
Comments:

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meta-info header:Error Codes
file version:1
type:5
time:1436228566516
name:Trouble Codes
codes:P0174,
codes_p:
codes_raw:43017400000000;;
codes_p_raw:NODATA;;
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Error Codes
P0174
System Too Lean
Short term fuel % trim Bank 1 (STFT1) -14.06 %
Long term fuel % trim Bank 1 (LTFT1) 17.18 %
Short term fuel % trim Bank 2 (STFT2) 7.81 %
Long term fuel % trim Bank 2 (LTFT2) 29.68 %
Vehicle speed (Speed) 0 MPH
Calculated engine load value (EngineLoad) 35.29 %
Engine RPM (RPM) 633 rpm
Engine coolant temperature (ECT) 161 °F
Fuel system status (FSS) Closedloop:usingO2sensorforfuelmix