ok i just wanted to know if i put LT headers, O/R H and coffin mufflers am i gonna need a retune...i know for the O2 sensor but what if i used MIL eliminaters but will it harm or set off anything if i did not retune for all this

 

You should do an intake and tuner as well...If your opening up the exhaust you should open up the intake as well. That way you will gain the maximum amount of HP and you'll have the tuner to make adjustment's for your set-up. You will "harmonize" your intake / exhaust and balance everything together. I believe you would need to tune for the headers anyway so you might as well do it right IMO.

 

yeah i guess i am just going to buy my mufflers then get the intake, headers, h-pipe in a combo with a SCT Xcal II tuner later