ok i'm swapping in the DOHC Zc this weekend... now my question is i wired my car for mpfi for the last SI swap i had in it... now the Zc harness is different... i know my existing harness will work but my question is i dont want any "check engine" light to come on like it was always on with my SI... for a reason i dont know about but... would it be better to use my ZC harness or it woulnt make any bit of a difference?