is it really necassary to use 2 o2 sensors if u have a b16 is a crx

 

not if you disable one with BRE

http://forum.pgmfi.org/

 

what is BRE

 

search topic b16, someone posted that in there. it is a software

 

well i didnt do anything with the other o2 sensor would it run any different?

 

if you have one plugged in and one not plugged in you are better off unplugging both. the car will run a little rich with them both unplugged but it will drive much better than only have one plugged in.
http://www.xenocron.com/services.php?page=chipping
just go there, ship him your ecu ask for a stock b16 map with o2 disabled,