I agree with something Karl pointed out in another thread: People throw in an old untested ECU and loom and expect them to work because they're newer than the MFi they're replacing. When they don't, EEC-IV (as in OFAB or OFAC; I guess that's what you were referring to by EFi) gets a bad rep.

If you're methodical and spend time on diagnostics and install, EEC-IV is a good upgrade to MFi. But it takes days to buzz out all of the cables and check the connectors so people skip that step and go straight to the last step: starting the car.

Lee