justin, if you are talking about the O2 sensor like my colleague pollytintop pointed out, there are two. One in front of the catalytic converter and one after. There are some really good instructions [http://www.allpar.com/neon/oxygen-sensor.html|on here.] If you are really ambitious, [http://www.keepandshare.com/doc/3144732/exhaust-pdf-september-16-2011-10-50-am-580k?da=y|here is] the part of the manual that deals with the exhaust and O2 sensor parts. Hope this will help. Good Luck