anyone reprogram an EEC-4 OBD-1

[ByronRACE]

Think of a tweecer as a chip with a usb port on it. You plug the tweecer into the Ford PCM, then plug your laptop into the tweecer's usb port. Now you run the tweecer software, and can modify anything you desire. When you're done, you remove the cable and leave the tweecer installed. If your PCM has no chip at all in the J3 port, either Massflow has figured out how to reflash the ford proprietary EPROM/EEPROM in the EEC-IV, or your PCM is a bone stock mustang box; which would explain why you're having problems. Open the box and look at the big dual inline package chips...if one of them is ceramic with a sticker on top covering a glass window, and if the sticker has Ford jargon all over it...you've got a factory PCM. That's an EPROM and the sticker has to be removed and the chip exposed to strong UV to erase it. Replace the sticker once you take a peek; or replace it with black tape.

Modern wideband sensors, even across brands, are accurate to about .2 AFR in the range of 15:1 to 10:1...some even wider, and even more accurate. Innovate makes very nice stuff that exceeds those specs.

Glad to hear you're not firing a bead blaster into the intake...I thought maybe the particulate was so small you were actually considering it. My bad.

Byron

ps, the external chip/tweecer like devices disable the onboard chip (there is a control line on the port for this purpose) and substitute off-board memory (their own chip that is interfaced to look like Fords original). The process is temporary....remove the external chip from the socket and the control line is no longer activated and the internal memory is enabled.