Has anyone installed NISMO Headers on the 06 or 05 pathfinder? I have the headers but still debating on the installation. Is it worth it? Would I lose gas mileage or gain?

So far I have installed a Throttle Body Spacer, NISMO Cold Air Intake, Flowmaster Exhaust.

 

I just located the web site for the throttle body spacers, did these improve your gas mileage?

 

I already have added the Throttle Body Spacer, Cold Air Intake and Exhaust. It has giving me HP and "pick up and go" but as far as gas mileage ...... depends if i'm always hitting the gas like i'm trying to race... no i lose mileage.. if i drive like i'm not in a hurry anywere, than yes... about 2-4 mpg. Besides that, it lowered my SUV's idleing rpm and the amount of rpm required to move.. for example, before the mods the rpm for idle will be at about 1.25 - 1.75 now the needle sits once the SUV is warmed up, at about .75 - 1.0. Same for when I speed up. It has dropped the rpm needle.

 

I just need to know, if its worth adding the headers. I know it will give me HP but will it help my MPG? If not, will it keep it the same and just provide performance? I have asked my friends and co-workers and i'm getting mixed answers and now i'm confused.