With any intake install make sure to to disconnect your neg cable when installing it, then back on when your done. This resets the ecu's memory and with new cai it will learn with the new one on. Should help out with being lean.

 

The '04 3V 5.4 would run lean if you looked at it wrong though. Resetting the memory did absolutely nothing, you pretty much had to have custom tuning to get rid of the CEL.

They fixed the problem though with the '05+ models