Hi all, i'm looking for any info on error code P1025 ("insufficient coolant temperature for closed loop fuel control") Any ideas as to what this means and how to repair it? I'v reset the computer twice and the code still returns so it's not a false code, i've also recently added a K&N filter and modified my 5.4L's airbox.

 

check your t-stat. if engine not getting warm. it will set this. or poss. the connector is loose at temp sender. maybe when you installed filter. make sure engine is getting up to oparating temp.