took mine off and havnet had any probs yet!!!

 

ive got a yosh RS-5 and took the one off over the pipe.....i left the one on the right side on....i pulled it off today and sprayed it with 1200-degree high-temp paint (low gloss) and it pretty much dissapeared from sight...blends in perfectly with the frame now...

is you swap pipes, you are pretty safe leaving the upper one off as long as you put the sticky aluminum tape on like it says...

 

i took mine off when I put on A 2 bros. s/o, but I did replace it's function with son self adhesion sound/ heat shield. I got it from an aircraft interior shop. works great.