Bad 02 sensor. Bank 1 is the pass side cylinders 1-4, bank 2 is driver side 5-8. Remove forward 02 sensor on the passenger side of the car and replace with a new one. Reset ECU and carry on. Hope this helps.
Check the wiring. Its possible for the O2 sensor harness to get up against the exhaust, melt through causing a bare spot, and then ground out the sensor.
Maybe actually that bank is running rich. Thats what the sensors are made for! Dont go just throwing o2 sensors in like everyone else. Possible causes can be a faulty spark plugs, vacuum leaks or a faulty pcv system.
brand new plugs with less than 1000 miles on them, however i do believe the car is running rich, but why wouldnt it just kick up a rich code and make life less complicated lol. yes they are bosch sensors. im under the car quite often, theres not any burnt up harness anywhere, what about this pcv system?