Long story short I have now replaced the sensor, valve (twice), and had the throttle body cleaned. I have tried spraying throttle body cleaner down the tubes that the sensor sits and still doesn't help. I continue to keep throwing either the insufficient flow code or the excessive flow code, most of the time it is the insufficient flow code, and have even thrown both at the same time After I do something, clean something, and/or change something I have the code erased and the next time the code comes up can be anywhere from 15miles to 250miles. My driving habits are the same each week day for the truck, to work 25miles - to lunch 5miles- to home 25miles. On the weekend and at nights we take my wife's Pilot.

Anybody got any ideas? I have read some responses on other threads that say check for possible leaks but have yet to read any replies that say that turned out to be the problem, or what specifically might be leaking to check. I am not real sure on how to even check for a leak.

I'm curious what the root cause of EGR problems was for other people in which a new sensor and valve didn't resolve the problem?

I put my second valve on last night and I noticed what appeared to be a little condensation in the valve I took off (tripped me CEL light today at lunch after being driven for 35miles on new valve). Is the condensation normal?

Any is help much appreciated.

2001 F150 XLT
4.6L V8
2wd

 

Did you check the DPFE sensor, known to fail. Lots of info on here about it, just do a search.

Good Luck

 

Already replaced the sensor. That was the first thing that just seemed to open up the can of worms. My actual problem does not seem to be with the sensor or valve sense I have already replaced both the sensor and valve (twice)

 

Ive seen EGR codes pop when the ports in the head are clogged with carbon deposit. Ive actually seen this more than once.

 

Clean the throttle body (must be removed to do so). The ports are most likelly clogged. This has also been discussed here.

 

Already had this done. I had this done at a shop, so I assumed they removed it to clean it. I will verify. In assuming they removed it to clean it they should have seen any large amounts of build up and thus cleaned it. All they said when they cleaned it was that it was dirty and showed signs of some carbon build up.

 

reese , there's know way they would clean your throttle bodie like you or I would - no way!!!! clogged ports = no-flow, which is insufuciant . This is more common with 4.6's and have seen this issue get resolved on here , only after they did it themselves. A good set of pipe-cleaners , B-12 Carb Cleaner. a 2 hour job.

http://www.fordf150.net/howto/throttlebodyclean.php

 

I agree they probably didn't do the best job in the world for sure. From examining it before and after they cleaned it I doubt they removed the whole thing. Some things that had to be removed to get it off didn't look like they had been touched.

But would clogged ports cause excessive flow? That's what is confusing to me because I will trip either insufficient flow or excessive flow, most of the time it is insufficient.

I was just trying to get a handle on things without sounding like an arss because it seems like every post about the EGR system is first replace sensor, second valve, and third clean throttle body. What if the problem is still there after all that?

Thanks for the article; who ever did that deserves a beer. I would imagine at most what the shop did was to remove the front portion of the throttle body (the part that the air filter hose connects on to). What do you call the back portion of the throttle body, the part that bolts on to the lower intake? Because if say I go buy a throttle body for my truck it only comes with the upper portion that is bolted to this part. I am referring to the pictures on page 2 of the article. I assume this is what you are talking about cleaning?

 

Hi!!

But would clogged ports cause excessive flow?

It's possible- Clogged ports could increase more flow in other areas in theory- given there is more than one path.



You get a better understanding from the diagram above, but if your interested , head over to Scorpio for it's complete structure and purpose.

http//www.fordscorpio.co.uk/egrmonitor.htm


What if the problem is still there after all that?

Well , a blower/supercharger would work lol. Seriously -I heard of certain ports in the head having an effect on said system, this could be possible. We just dealing with the most probable. The easy stuff first

The piece your referring to is the TB elbow - Upper intake/Throttle body/Elbow/Lower intake/ Plenum/ Block. That's how it's stacked.

There's a few of us including me that port and polish the throttle body and elbow. Your IAC controller is part of the elbow and this controls your idol (how she purrs) Clean this well (I hope you have compressed air on tap)Blowing compressed air threw the IAC w/WD 40 and hand working carefully makes her purr like a baby kitten.

Good Luck

 

Just plug it, call it good. I did, no problems so far, 20k miles without it.

 

So you pretty much ditched the whole EGR system?

Ive been wondering lately if this is possible-plug the holes in the intake and exhaust and rip off all the EGR crap. Truck still runs right without it?
Any computer tuning that would need to be done to delete the EGR?

 

Some background on how this system works then some deduction.
The DPFE sensor only measures flow across a restriction in the main tube after the PCM sets up the conditions and can report the flow results. Excessive flow and detection of some conditions with the connecting hoses to the DPFE can be made by the PCM program.
Some deductions: Excessive flow can be a rusted or cracked main tube, the restriction has come loose inside the tube and changes position, the EGR has stuck off it's seat.
Insufficient flow; The DPFE, the restriction is plugged, EGR not open per command, ports in manifold are plugged.
Moisture; the exhaust is full of moisture and condenses on the coolest surfaces along with it's carbon in suspension.
The flow test is usually not done until all other EGR tests pass or the DPFE test means nothing.
In cold temps below freezing this moisture can freeze and cause blockage of the restriction on a temporary basis so the flow test is not done until later in a drive cycle or on a second cycle to be sure the freezing blockage is not taken as a positive blockage and sets a code, falsely.
This is all documented in Ford OBDII discriptions of operation.
You or someone has to look a little harder and be sure the inspection and work was in fact, done.
There is no more to it than this.

 

You can Plug it - Damn I can't remember where I read this , if you plug it your pay for it in HP loss, that's why people stopped doing that.

 

Thanks! "We just dealing with the most probable. The easy stuff first " I know that was why I had put in the first post that the easy stuff had been done because on other related threads it seems like after a few people post to replace sensor, valve, and clean the throttle body that the thread never gets responded to again. It may just be the thread starter doesn't do anything to bump it back to the top and/or doesn't post what actually solved the problem.

I know that the shop did not remove the throttle body elbow for sure.

Anyway thanks for the diagram. One question, I have not read in any other related threads or in this one anyone mentioning the regulator, it's always the valve and the sensor. Could it be possible that the regulator might be going bad or is bad? Is there a check from the PCM since it has electrical to it that checks the regulator? The reason I ask is that I will throw both codes and the regulator creates the vacuum that makes the valve open, right? What do regulators run? The valve and sensor were not that bad and easy to change. It has turned very cold were I am and I do not have a garage to work on the truck and don't want to freeze by b@!$$ off cleaning the throttle body, elbow, and egr pipes. Also only compressed air I have on tap is when I eat Taco Bell. So I will have to have the cleaning done at a shop, maybe this time I will be a little more specific on that the clean the throttle body, TB elbow,, IAC, and egr ports off the manifold at the minimum.

I am by no means a mechanic which is why I don't answer any of the mechanical threads and ask you guys (the experts) . Electronics and electrical on the other hand, that is my ball park.

 

Thanks! I am curious about the regulator. How does it get checked? It's the only piece of the system that I have not changed..