Zero off throttle probs + check engine light

2007 Ski Nautique with Excalibur and ZO. A few weeks ago we noticed when we drop a skier and bump into reverse most of the time the Check engine light flashes for about 3 seconds. Temp and oil looks good, but the oil pressure may drop to about 24 psi according to gauge. Thought maybe 25 psi is the limit for the system and maybe the sender is getting tired.

This weekend when I'd take off to pull up a skier I'd throttle down and it was like there's nothing there, go to reverse and same thing. Move the controller down and no revs. Just in gear idle. Once skier is in, pop open dog house, swap drivers, etc and problems stops. Every time it's done it we noticed a slight whining noise from possibly rear of engine. Today when it did It i noticed RPM's jumped maybe 50 turns. Suggestions?

Haven't looked closely at how ZO controls the throttle, but that sounds a bit like how a PP cable can get pulled out and will rewind itself. Prior to the rewind, you have reduced throttle action.

I'm assuming that the oil/alarm issue is unrelated.