Im still leaning towards a manifold gasket leak. Im guessing at the base of the throttle body. After having done all this work, have you reset the computer? If its throwing a lean code, your getting a lot of air from somewhere. Can you hear what sounds like air rushing anywhere from the motor? Or maybe even a whistle?

Dan

92 Rodeo, 3.1 TB crank, custom bumpstop spacers, DOR shackles, Flipped ball joints, D44 Rear, 4.56s and new magnaflow cat and dynomax ultraflow muffler Since been replaced by a 2 door Explorer on 31's shackles, cranked torsion bars and full exhaust