help i'm lost

[wwr]

I hope i.m in the right area so here goes I have a 05 itasca 8.1 i'm getting 131-151 codes low voltage rt & lf o2 senors changed senors test rove 90 miles light came back on major power loss reset and babied home. Found small exhaust leak repaired( changed donuts) ,changed coils,plugs and wires test drove 90 miles light back on double checked wiring cleaned made sure good connection retest same results. Help