S type voltage issues


Just looking for some advice. I own a 2003 S type basic 3L V6 and I recently had the alternator replaced but I put a duralast alternator on it and not the certified part. The battery is charging at 14.2 volts but I’m getting battery and check engine codes saying that the car needs 15 volts. Is this something I should worry about and why or why not?

Hi Jake. Sorry I cant help…
Anyway, I notice that a lot of members own older and perhaps “more desirable” cars.
I’ve had limited help with issues related to my “Modern S-Type”
I hope you can get the answers you need.
Kind regards