EGR code P0401

[CZSteve]

CEL comes on with code P0401
"exhaust gas recirculation flow insufficient detected"

This is on a '98 Mercury Mountaineer 5.0 2WD w/ 99,300 miles.

A few months ago I replaced the EGR valve and the light came on within a day or two of driving - I assumed that I just needed to have the code cleared.

I recently ordered a Digimoto for the lap top - code still comes up as P0401, cleared it and the code still comes back within a few miles.

I had bought the EGR valve from AutoZone. What are the chances the new valve was bad? Not much to wrong with new valve is there?
Anything alse that would cause this same code?

BTW:
We also have the dreaded 'bird chirp' - I'm assuming it's the CMP drive gear.
But, I did notice 'Ol Ben' mentions this from the following thread:
http://www.explorerforum.com/forums/showthread.php?t=146928&page=4&pp=20

I recall reading a few years ago that the chirping was due to a emission control component in the passenger side exhaust manifold. After things warmed up enough it would go away. My 93 had this chirping sound that sounded like a bunch of birds under the hood. Like yours it appeared shorytly after startup than would eventually go away. I ignored it and after a few months - maybe 1/2 a year or more- it has fairly well gone. I have about 225k on the clock now.

Any insight would be greatly appreciated - this is my wife's car...enough said.

 

[FixIt]

replace the PFE sensor

it will have 2 hoses and plug. The hoses go down to the exhaust manifold. The plug will have three wires. Your old PFE sensor might be made of aluminum. There are two types of PFE sensors. Those that are bad and those that will go bad. Every PFE sensor that is made of aluminum goes bad from the exhaust gas. Don't buy anything from Auto Zone. Their parts are cheaper in price cause they are cheaper in quality. I am an ASE Certified Master Tech with Advanced L1 certification. Get this PFE sensor at the dealer. It will probably be made of black plastic and will bolt right up. You might need to replace one or both of the hoses going to it if they aren't long enough to reach the redesigned PFE sensor.

 

[CZSteve]

FixIt - thanks

The Haynes manuel (sorry, it's the only book I have) shows a DPFE sensor mounted to the side of a valve cover behond the oil dip stick tube.

I just looked w/ a flashlight and didn't see it with an initial glance.
Can you point me to where it is located on the 5.0 on a 1998?
I'll take a closer look during the day.

Thanks again.

 

[Turdle]

Follow the two vacuum line looking things coming off the egr tube. They go to the dpfe