914turboford

I'm running a 2001 4.8 LR4 in my 1984 Corvette chassis that has been rebodied as a CJ7. Search this forum for CJ7 Corvette if you are interested. Car weighs about 2600 lbs. I want to get nearly 30 mpg on the freeway (maybe not realistic, not as areo as an F Body or Vette). I don't want VATS or rear O2's of course. I want to maintain stock horsepower (270 I think?). I have no cats and a CAI for my only engine mods. I am running an F body 4L60E. 2.73 rear end ratio. 26" outside diameter tires. Is there a way to program the ecu so that I can read codes without a scanner like an OBDI car? So what should I have done? I'm about to send out the ecu.