[HydroJim]

If you're looking to run lean burn, you need an EFIE.

EFIE is a dirty way to make a simple ECU run in lean burn mode. I don't recommend it. In fact, I recommend not even trying to mess with your ECU unless you do a lot of research first. Best thing would be a megasquirt ECU set-up but that takes a lot of time and dedication.

I know all about this so if you want more info let me know.

Open loop will never get you good MPG. it's the mode used to keep your car running when sensors fail.