Infiniti I30t 2000 w/80k miles

Car has a lot of miles so should i replace my 02 sensors.. and my questions about them---


How do i replace them/ it?

where are they located?

80k miles on car. how much perfomance will i get back?

what kind do i buy?

how much will this cost?

" theres prob a link to all my answers but of course my search feature doesnt work"

 

any info would be great.. or a link to the " how to"

 

no info? come on

 

For Maxima, one O2 sensor is located at the header, bottom of the car. The other one is located at mid-pipe.

 

If you are Fed spec you have 3 O2s and if you are Cali. like me you have 4 (1 in each header and one near each pre-cat).

How do you know that you need new O2s? Is your car running badly/ throwing codes?