Volvo Forums - Volvo Enthusiasts Forum - 2011 Volvo Penta 5.0 GXI Problems

Looking to see if anyone is having issues with their cat? I am getting alarms and engine goes into limp mode, has to be cooled right down for a couple of hours at least, then will be fine again. Scanned and always different codes. Did find right side manifold is much hotter than left side. Found water boxes to be seized inside, took apart and cleaned, seemed better but not for long. Now tried to run without internals worked good for a day, the same happened after idling for a long period of time waiting to load at the dock. Now I have bank 1 and bank 2 codes, and miss fires on cyl 3 & 5, defiantly have a bad miss, have ordered new o2 sensors not here yet.
Thanks for any help or info