So I have a 2010 5.7 GI Volvo Penta DPX that runs fine for the 1st few hours and then is going into slow mode (won’t run above idle) I can shut the motor off and it will run fine for about 30 seconds and then goes back into slow mode. I’m guessing there is a wire shorted somewhere, but puzzled as to finding it. I know there are ways to make a code reader to help at least track down the circuit to narrow down the search. My question is in all the research I have done, I have only found older versions and the OBD plugs are different than mine. Does anyone have an idea on where to look or how to proceed?