i have my tune about lined out. my only problem is when i'm cruesing on the interstate around 70mph i can roll into boost with as little as 37% throttle some time less. around this area the a/f is good right around 11.5. but if i give it to 40% where the pe and be come in it goes all the way down to 9.5. how do i lean this area out? this is all around 2000 rpm.