I wouldn't split hairs on exahust pipe size. While I'm sure it could be optimized for FE, I don't expect that to be the need in this case. I have an oversized exhaust pipe as well. I like to use my car for more than just good FE. Even when I go drag racing, I am still getting great FE
I want my cake, with frosting and I want to eat it too! Lean Burn is the frosting
