I recently converted to E85 by swapping to 42lb injectors without a tune. Ran two full tanks through without a problem. Car loved the corn juice. Killed all my knock! LTFT settled in between 10-11. Life was good.
Until...
My last fill up. Shortly after topping up this last time, my LTFT began creeping up. To the point where I'm at 16.4 under acceleration and while cruising. Even set a MIL. (P0170 Bank 1 too lean.) I am almost certain it's fuel related because it happened right after my last fill up, and all my mechanical maintenance is up to snuff. New(ish) plugs, wires, fuel filter, and a walbro 255 pump. Rail pressure is about 45 while parked.
So here's my question:
Can I throw a couple gallons of 91 in the tank to try to bring my trims down? Would this hurt anything?
