Rattle after installing headers
 

This is the deal, I installed some Borla UEL headers on my 2013 FR-S and it now has a rattle. This happens when the engine is warming up and I am just taking off after turning it on. I thought it might be the washers on the O2 sensors but they are tight.:bonk:

Most likely header caused the overpipe to shift closer to subframe causing rattle. you'll need to readjust things a bit so there's clearance.