I had these three codes during a ride several weeks ago, 65590 is misfire detected cylinder not identified, 65592 is misfire cylinder 2 (mag), and 520344 – 17. Research suggested it might be the O2 sensor or TPS.
I took it to the dealer where it was purchased (4 Seasons Motorsports Rye, AZ.) and it turned out to be the fuel pump and 1 bad fuel injector. Extended warranty picked up the fuel pump, I had to pay for the fuel injector. Took it for a ride when I picked it up yesterday, runs great.
Thanks Nate for getting us up and running again just in time to enjoy AZ RZR riding season.

Utah RZR Rentals