O2 sensors
Hey guys my wifes 2006 toyota carolla le has the
check engine light on and after hooking it up at
autozone I was told it could be the cat or a bad 02
sensor. So the wife went and ordered 1 upstream
and 1 downstream. I have never dealt with these
sensors before so I don't really know exactly what
I'm doing. Lol XD. I just have a hard time
understanding the difference between an upstream
and a downstream sensor besides where its
placed. I heard there was no difference between
the 2 sensors themselves annd it doesn't matter
which one goes where, then again I also heard it is
very critical that it goes in the correct place. What
should I do? Any help would be great, thanks!