97 chevy 5.7 ses light on multiple dtc

I drove my truck (97 chevy 5.7 vortec 180,000 miles) to the store today and noticed the ses light on. 4 Codes came back as P0300 random/multiple cylinder misfire, p0175 system rich bank 2, p0172 system rich bank 1, p0161 o2s heater ckt malfunction 2/2. I know the P0161 is o2 sensor between cat and muffler on passenger side and tomorrow I will check the wiring to make sure I don’t have a melted or chaffed wire. And I could tell I have had a misfire going on because it idles rough after reaching operating temp but seems to run fine on cold startup . I have only owned the truck for this last 20,000 miles so I don’t have a service history and I know these engines have spider injector/ pressure regulator problems and I have dreaded I might have this issue because I don’t know if these parts have been replaced in the past. Can the multiple cylinder misfire be caused by the rich condition? Or maybe the o2 sensor heater issue is linked to the other sensors reading the rich condition? o2s11 and o2s21 swing between 0.1 and 0.9 on my actron cp9185 and o2s12 hangs around 0.035 at idle and o2s22 sticks close to 0.065.Any help would be greatly appreciated.