ok so i have both the sensors out for the header and dp. the header came with a bung. should i put sensor back in header and put bung in dp or what? im setup to run catless on my tune so i doubt ill thow a code either way. thanks

 

It doesn't really matter if you're already tuned out.

 

Put the front O2 back in...don't worry about the rear.

 

yea put the front in, and forget the rear. but if you have the hole you might as well just plug it in.