pretty sure the cat is bad since i continued to get cat efficiency codes and since moneys tight now i tried the antifoer trick on the car to buy time. no more cat codes. instead im getting a p0136 and p0137 codes both pretaining to voltage problems intl the circuit. both codes are coming up as pending dtcs. no corrossion on wiring or plugs. new rear o2 as well. rear sensor is showing .600v when running and warmed up. need help thanks

ed