Yeah the subject vehicle is OT,but I post this for those of you who
get a kick out of us tortured souls being victomized by mechanical
meyham. The object of my obsessive battle is the Check Engine Light
attached to the Ford pickup left to me by my deceased father. Dad
drove this thing for a couple of years with the CEL glowing brightly
in his daily travels.When the annoyance factor became too great,it was
hidden behind a cleverly placed hunk of electrical tape.WA-LAAA! Outta
sight,outta mind.
 I ,on the other hand,prefer it to operate properly,not in the limp
home mode the computer reverts to when a hard code is locked in the
memory.The driveability and mileage suffer if the lights on.So I plug
in the trusty Snap-On scanner and unlock the hidden trouble
codes....Faulty downstream O2 sensor. Ok,off to the parts store for a
new one.By their computer,my truck is supposed to have 4 (!) O2
sensors,2 before the converter(upstream) and 2 after(downstream). Mine
only has 2,one in each exhaust manifold,ala'the prior years emission
package.Typical Ford,use up last years stuff on this years model.So I
buy 2 new sensors ($91.00@ pair)  and throw the truck on the hoist for
access. Damn lucky I had a hot wrench because the manifolds had to be
cherry red before the sensors would unthread. Install new,clear code
and cruise.Right?? NOT!!!
 After a few miles,my  CEL is once again a glowing.Rescan the
computer memory,and the new magic code is "low EGR flow." Wonderfull.
Silly me replaces the EGR ($54.00) and 1 questionable vacuum line to
it).Clear code and drive. Light is off for a good 8 miles driving.Shut
it off and let sit for 1/2 hour,then hop in to go.5.375 nimutes after
restarting my CEL is again illuminated.Now WTF??!!?? So this time I
throw it at a new ATC scanner  for comparison.Same "lowflow" code.So
after confiring with a late model service tech friend (who states they
see A LOT of EGR flow codes these days), I follow his advise and
remove new EGR valve and run a length of wire into intake plenium to
remove and carbon crud blockage.I also start it with the EGR supply
tube disconnected from the new EGR valve and tack it up to 5ooo RPM a
couple of times to hopefully blow out the pipe. Optimisticly,or
niavely,you choose,I reattach all the pieces and plumbing and drive it
around.The light remains mute,so I think I got it wipped.Drove all day
like that,and was starting to get happy.Then,just as the front tires
touched the driveway after work the CEL turns on AGAIN,and in my head
I hear the ECM laughing at me. Next morning I  remember a friend gave
me a Haynes manual. While mot as good as a MOTOR manual,its better
than nothing! So I follow the diagnastic flow chart,which leads me to
the "exhaust gas regulator",which is a electromechanical solonoid that
regulates vacuum to the EGR. So I call my local FLAPS,and John tells
me he has the "exhaust gas flow sensor",but not the solonoid."What?" I
ask,this is the first I have heard of such an item.
 So guessing since the EGR is new,it has a unfettered supply of
exhaust to it and all vacuum lines are 100%,the logical item is the
thing that regulates vacuum to the EGR. So we pay a visit to my
FLFD,and $51 bucks later,I have another shiney new part
underhood.Clear the trouble code and drive to work. About 2645 feet
from the parking light my old friend the CEL is lit up again!!! @#
%@*&*#*&!!!!!
So being of pissed mind and aggravated state,I hop on the net for a
Google of Ford EGR code issues.OMG!!! Quite the popular issue.Wish I
would have surfed first. So if I believe what I have read,I need the
"flow sensor"( for another $45 dollars). Aint technology grand??!!??
Hope to hell this cures the issue cause I am going batty.! Thanks for
letting me vent!!!...........Rich