1345 when engine is cold

This code, 1345, has been popping up recently when i start my blazer for the first time in the day (it was single digit to negative temps the nights before). I know it means cam to crank position correlation fault but dunno what it actually means (seems fuel pressure related according to old posts) it doesn't come up any other time even if i drive to work in the morning and has been sitting all day till i go home around 9, just after overnight. Just wanna know if it's anything i should worry about. I should mention that i've installed a k & N drop in filter and other codes have shown up but they haven't come back since, just this one.