Troubleshhoting misfire and low EGR flow

[Mortis]

my explorer is a 2002 eddie baurer. w/ 4.7. and tow-package.
I have had thes two codes before.. low egr flow and misfire.
now upon removing the EGR valve , i found no carbon builtup..super clean.the diaphram works fine ..holds a vaccum,no leaks..the geen plastic tube to the sensor has no kinks breaks or leaks,..this low EGR flow code is the secong time i got this...went away about a year ago....
?????? sensor..how to check..this little bugger aint cheap.

now the misfire....replaces all plugs .wires are all good. only misfire at idle .semi-rough..not real noticeable at take-from from a dead stop. but noticable.. no head jerkin hesitation misfire..
when out of idle all is fine..no misfires at speed .

Seems to come and go.....

something sticking??

25 yrs experiance in mechanics.....been building muscle /hot rods for years as a hobby..but these computer.sensor cars...DAMN its a headache at times..lol

 

[prerunner02]

try cleaning your dpfe with electric motor contact cleaner, then dry it with compressed air. should do the trick.

 

[rrgone]

Without knowing specifically what codes you are getting it's hard to make recommendations. If it was P14xx than I suggest getting a new Motorcraft DFPE, which is about a 10 minute job to replace. The DFPE sensor can be had from online Ford parts sellers for about $50 shipped. They improved the design sometime after the 2002 model year. Aftermarket are about $35 but are more likely to fail again.

You should also have a look at Sybertiger's thread here: http://www.explorerforum.com/forums//showthread.php?t=217062 You could have a vacuum leak.

Good luck.

 

[Mortis]

well i replaces the sensor..ran ok for about 10-15 miles..then st started again .now it kinda lopes...misfire under accel and at midrange accel @ around 2000 rpm 60 mph...and the eng.light flashes.the steady..
..eng will smooth out at a steady speed...but aint right.

i get the feeling it spark plugs but i just replaced them...it ran great for a week..then " eng light"
' again" flash..then steady. ...are these platnums crap?

 

[Mortis]

Ok went out an bought myself an OBDII CODE READER.

this is what came up.

#1 P0304 generic #4 cyl misfire
#2 P0122 generic throttle positioning sensor cuircut low input.
#3 PO300 generic random misfires.

suggestions beside replaciong the obviuos 2 items...what could ALSO cause these code..if any.?

 

[alexk]

Brought mine in today for misfire at idle, and it was the coil that the spark plug sits on for cylinder #8. They charged me $67 to replace the coil and while they were at it I had them do a tune up for $179. Now if I could just get rid of this terriblw migrane life would be great.

 

[Mortis]

well repositioned the #4 cyl plug AND coil to the #1 cyl.position..took it for a test drive after clearing .he codes. Smoother.but still some missing..did an accelerated take off from stop...got a blinking " eng light " at 65-75..decellerated to 55 and light went out. this happed twice.
rechecked codes..same codes..#4 cyl misfire and randome misfies..w a blinking "EV" code on the reader..
now the eng runs rough at idle..shakes.

shut eng down . cleared codes again.restarted and let idle..
eng light came on..same codes: po300,po304

:thumbdwn:

freezeframe data.
fuel sys. 1 CL
fuel sys 2 NA
Calc Load(%) 29.41
Eng RPM, 660
Ven speed 0