Q: 2008 Ford fusion, stalls out while driving

Re-flashing the PCM, or replacing the PCM, is the very last step in a many pages long diagnostic routine for the throttle body. Were all steps in the Ford diagnostic specified for the throttle body actually performed? If not, the fault might have been found within the "decision tree" in that diagnostic and, again, re-flashing the PCM would be irrelevant. If at this point, codes do exist, those codes could be used as a "new" starting point in the diagnostic. If the codes are not relevant though, basically what you have to do is start with all of the possible causes of immediate stalling and those include items other than the throttle body. I would also have a question as to "vendor" that supplied the throttle body. Who knows, it might be defective (especially a consideration if it is "re-manufactured and not supplied by Ford) but, again, even in that case if the specific (and lengthy) throttle body diagnostic in the Factory Service Manual was followed, that would have been discovered. A mechanic would have to look at this and "take it from the top". To get this resolved without further delay, what I would recommend is just request a check engine light diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.