I have a new O2 sensor I need to install in my '97 Eclipse, 2.0 non-turbo. Installing to try to fix a "System Too Lean (Bank 1)" error and really low mpg.

Do I need to replace the upstream or downstream sensor, and how do I do it? Appreciate any pointers...

 

That would be the first o2 sensor after the exhaust manifold. You need either an open ended wrench or an o2 socket to remove it. You'll also need anti-seize for the o2 threads, unless it comes with the o2 sensor. Anti-seize is highly recommended bud

Oh, forgot to mention...I suggest an OEM replacement over the universal just to keep from getting confused with what wires go where...most of them aren't very clear to folks who've never done it before.

 

Thanks! Just so I don't do something dumb, is the O2 sensor highlighted in blue below the right one?



Thanks!