Dazed and Confused
Join Date: May 2012
Location: Upstate New York
Re: Stumped... 93 Ford Festiva
The car has some years on it, are the O2 sensors original, or don't you know? It sounds like the sensors need to be replaced, which would explain the lean code as well as the O2 diagnostics. The lack in back pressure would only improve power, but you could have a plugged exhaust. Does it maintain a steady idle, or does it seem to hunt at times? The computer really controls fuel flow via vacuum regulation which is controlled by the throttle body... in a sense. I think the first thing I'd be doing is checking the vacuum lines and looking for potential leaks, get your O2 replaced if that's needed, and find out what your fuel rail pressure is.
Ever notice that there's so many high performance parts available for GM products?
Did you ever think that maybe they NEED them?