I am getting a backfire or two on the shifts. i am seeing negative timing numbers at the shift and i think that combined with no fuel cut is causing the backfire.
i have logs when it was stock on gasoline and then mostly stock but with e85 and it was still cutting fuel then but now with some boost it no longer cuts the fuel.
any idea how i get that back. i tried going back to my old tune other than a couple of setting like injector size and maf table and that didn't bring it back. i suspect it is an air mass thing but i cant find anything obvious.