360 code po422

i keep getting slow down light when car has sat for an hour or longer flashes for 2 mins than goes away,no loss of power while light on,so far dealership has changed both sides cat probes and cat ecu temp sensors,the car is a 01 360 spider f1 with 13k miles.i think last time the code was po422 right side no ck eng light comes on.what is po422 and does the 360 workshop manual have def of codes?

 

thanks