Warranty stickers after housing replacement?

Hi all,

I have an iPhone 6 Space Gray (unlocked). I recently replaced the back gray housing with a gold housing as the old housing looked super beat up (from a case that had debris although I will say it looks like it hit concrete). My phone is less than a year old and now I am having issues with the touchid sensor not working at all. I was wondering if Apple would be able to tell I had replaced the part if I reinstall the original space grey housing? I don't believe this issue is related to the housing replacement as my phone has had the new housing for several months and the issue started as of two weeks ago.