o2 sensors

I have searched the forum/google/youtube and I couldn't seem to find anything that answered my question. Sorry if this has been answered before. After taking my 2007 FJ with 135k miles on it to autozone and getting my codes read they said I needed a new cat converter, I researched on here and...

I have a 2007 FJ Cruiser and have been trying to do all the repairs myself but finding some barriers to this. Last month my FJ began stuttering and lost power so I hooked it to the computer and the O2 sensor codes were indicated. I changed pre- Cat sensors and everything seemed great over the...