Can any one give me any ideas on where to begin with fixing these codes pulled?? on 2000 Toyota Camry

I have four different codes from my 2000 v6 Camry causing my check engine light to be on, the codes are p0135, p0325, p0441 and, p0446. I don't know were to start replacing parts.

Asked by for the 2000 Toyota Camry
2 answers 1 comment
DON'T just start repl parts that is costly.seek proper diag as to issues,it could be circuit issues or sensor issues. it will save you money in the long run
Ok. thank you for the advice! I thought it might be an O2 sensor but just wasn't sure.
maybe you could start with the first one, the ho2s and the knock sensor first