That definitely sounds like a fuel obstruction, but may simply be that she
got some bad gas. Has there been a long spell of cool wet weather recently
where you live? Did she buy gas at a discount place?

It is important to have the diagnostic codes scanned as soon as possible,
since there are a variety of other possible causes i.e. electrical
connection. The computer only keeps these codes for a limited period of
time.

I'd check to see if the work was done when they said and also how much has it
been driven since then ? Would you still have had older gas in it ? I live in
PA. and I don't know when they changed from winter to summer formulas but it
would affect drivibility too..there are a lot of variables like how much it's
driven - what work has been done to it already...when my fuel pump was dying it
would act like that too and who's to say you didn't get a bad pump. Good luck
and let us know. Linda

Today, I was driving it, and for about 20 miles, everything was ok.  I
filled it up with gas, and even got the oil changed.  On the way home,
I turned onto another road, and about 200 feet down, as I was giving
it gas, the tach just started going down until it was under 1000.  I
pulled off the road, shut it off, and sat there a while, like what my
wife did when it happened to her.  We've probably driven about 2000
miles since the warranty work was done on the fuel sender, and we
bought gas a Sam's club, the same place my daughter gets it from, and
her 2002 Focus is running just fine.

After setting there for about 3 minutes, I started the car and it ran
like normal, so I put it in gear and went down the road about a half
mile, and it did it again.  Now, no matter how long I sat, when I
started it, it would start, but the rpm's would go above 800.
Finally, I left it idling roughly while I got out and looked under the
hood.  I remember when I got the oil changed quite a while ago, the
attendant said that they couldn't open up the compartment to check the
air cleaner because of Ford's flimsy mounting screws, and the nut was
spinning and so......the air cleaner hasn't been checked for a while.

There is a plug on the air intake tube, and I unplugged it, and the
engine revved up to normal.  I closed the hood, and drove the car
home, although it was shifting a little harder than usual.  I took my
Haynes repair manual out and found out that I unplugged the "Air Flow
Sensor."  

Tomorrow am, I'm going to open up the air filter to check it.  That
may be my problem, but somehow, I can't believe it could be that
plugged up.  I'll let you know how it goes.  Thanks for the
follow-ups, and advice.