I Pulled the CKP sensor and the end was "scored" up and the metal magnet is kinda covered with the plastic like the plastic was "chewed" a little and mushed over the magnet. I know these are all technical terms but the best I can describe it. Does that sound like the problem?
I would check to see what chewed it up, otherwise it may do it to the new crank sensor. Starting with the oil filter sounds like good advise. Good luck