Hello all, I’ve recently been monitoring my car with my scanner while driving home from work at night because my fuel mileage as of late has been absolutely trash with no indication as to why my car has new plugs, new injectors, new air filter, new PCV valve and a recent valve adjustment with throttle body cleaning.

The other night I was monitoring EGR commanded and EGR error, I noticed my egr error would never change from 99.2% and my commanded would sometimes change slightly. After doing some research online I found that if a scanner is reading 99.2 on the EGR error the valve is either stuck or the position sensor itself isn’t working.

When I got home I removed the valve and cleaned it out good with carb cleaner and also worked the valve open and closed many times, I put it back on a went for a drive my EGR commanded and EGR error both started to change and when commanded would go to 0 so would egr error. After about an hour they both stopped moving again but commanded would glitch from 0 to 99.2 rapidly now they just both stay at 0 all the time no matter what.

could anyone with a scanner handy monitor these two settings for me next time they are out for a drive and let me know if they are also stuck in one position or if I have an actual issue here that for some reason doesn’t throw a code.

thanks for the help in advance 👍🏻

 

I can monitor it on my ride home today. I just bought my 09 w/ 90k and previous owner (not the first owner, they were cool) neglected a lot of maintenance on it. This weekend I did a valve adjustment, plugs, air filter, etc so it should be running well. Remember to there egr ports in the intake manifold, which can be accessed via the plate on the IM facing the radiator. I've seem a YT vid that goes through the cleaning procedure on that.

Also we are on winter blend gas, so the combination of different gas and colder intake temps results in reduced fuel economy. I have found in previous cars that grill blocks help to keep the engine warm, and increase intake temps. Increasing intake temps automatically will increase fuel economy as colder air is more dense, and REQUIRES more fuel. I did just do a full grill block, upper and lower, and it was too much, and it was getting too warm. So I removed one section on the lower grill, and temps are fine.

 

Ive cleaned my egr ports but quite honestly there was nothing in them, I even sprayed seafoam from the valve port until it came out of the intake manifold it came through without issue. My mileage usually drops off in the winter but I’m struggling to get 400kms to a tank when I used to average 600 in the summer and around 550 in the winter I know there is an issue I’m just trying to narrow it down.

 

I'll also get a comparison for you via torque app.

Spark plugs too new to check for color?
I'd offer for your consideration that if the engine is running well, sounds good, and has no codes (once we assess EGR) maybe consider non-engine causes for worse fuel economy. Rolling resistance from alignment, brakes, what have you.

 

Thank you I appreciate it, I’m interested to see if others operate normally or regularly and mine is stuck but not throwing a code. I don’t believe the plugs are old enough to tell me anything as the car seems to run fine. I actually just did the brakes on it so they are brand new nice and free the car rolls on it’s own nice an easy while in neutral. I also had an alignment done last winter after I got new tires put on. I honestly see nothing else with the car that has caught my attention other than this.

 

So EGR at idle will typically be closed, which is what you are seeing. I found yesterday leaving work in 35*f temps, the EGR error was 99.28%. While driving after the engine warmed up and the ECM called for the EGR to open, the ERRORS did bounce around as the EGR was opened and closed, which made sense. This morning leaving my heated garage, the EGR error was 0, which is telling me that temps might account for the error of 99.28% I was seeing after I left work.

 

So once your car is up to temp it will start operating regularly while driving? Because mine is always at 0

 

Which reading is always at zero? Command EGR or EGR error? If your ECM is commanding the valve open, and it doesn't open it will show the error of the percentage it is supposed to be open. Whereas if it opens, but not the correct amount it will show a % error.

I got my info from reading through this article yesterday. EGR Sh!t

Taken from the article.

EGR ERROR = EGR_ERR: This parameter is displayed in percentage and represents EGR position errors. The EGR Error is also normalized for all types of EGR systems. The reading is based on a simple formula: (Actual EGR Position − Commanded EGR) ÷ Commanded EGR = EGR Error. For example, if the EGR valve is commanded open 10% and the EGR valve moves only 5% (5% − 10%) ÷ 10% = −50% error. If the scan tool displays EGR Error at 99.2% and the EGR is commanded OFF, this indicates that the PCM is receiving information that the EGR valve position is greater than 0%. This may be due to an EGR valve that is stuck partially open or a malfunctioning EGR position sensor.

 

My commanded EGR is always at 0 it never moves and my egr error is always at 99.2, so does your car start commanding egr once it’s up to temp all the time? Because after I removed mine and cleaned it, it started moving around for about an hour and it hasn’t moved once since.

 

EGR is constantly adjusting while driving after engine is up to temp. Weird that it isn't commanding it at all. Read up on that article, I remember reading that it might be vacuum related?

 

yes that’s why I’m trying to figure out a solution as to why it isn’t. What is your car reading for engine coolant temp? My car appears to be warm but maybe my temp sensor or thermostat need to be replaced before I throw a new egr valve on it. It’s also weird that I have no engine codes or anything related to it. I have read up on the egr system quite extensively which is why I came here asking someone to verify that mine is in fact not working now I just need to figure out why and it will hopefully help others in the future.

 

176 deg most of the time. I would check vacuum, long term fuel trims, air/fuel ratio, and timing.

 

These were all taken between warm up (indicated in the 4th image) and putting around between 1st and 3rd in the neighborhood. I think peak rpm was 4k in 1st, peak speed was around 35mph.

EDIT: worth mentioning that EGR commanded was 0 when idle/clutch in/coasting neutral. It read as 99.22 error at those times. Took a second either to recognize or engage when accelerating.

I think since you have no CEL/codes, we need to attempt to figure out what status/conditions shut off of EGR without throwing a code.
Be much easier though to suggest double-checking your most recent work on the car for anything amiss.

I know you're quite experienced and don't mean any offense with that suggestion. I'll still check the bishko manual to see what I can drum up for EGR not opening

 

Thank you for that info it’s very helpful and I really appreciate it!

I monitored my car tonight on the way home and everything seems pretty similar to what you have shown here aside from the air/fuel ratio as my scanner just shows me the voltage not the actual value. I did monitor it on a single scale by itself and it seems to have a decent range.

I checked over my car a couple days ago and can’t see anything that would cause this that wouldn’t cause a light, but you’re correct there must be something that the ecu isn’t receiving or the egr valve stepper motor/position sensor is no good but doesn’t have an open circuit or short that’s causing a light. I’ve swapped engines on Hondas before and had engine lights come on that was resolved by plugging the sensor back in not even doing anything. I will get the pinout for the egr valve and remove it to test the stepper motor and verify it is infact opening and closing. I’ll also pull it open with the key on engine off to verify the position sensor is operating. It’s also possible the valve is working as it should but the position sensor is not reading and that’s why I get the 99.2 off and on all the time when I’m driving.

 

I've been waist - neck - eyeball deep in resolving this

It's all done now and doing a more extensive test drive today, but this freakin ford has really put my confidence to the test... The lesson learned was that even if spring-type hose clamps seem insanely over-tight for their application I shouldn't swap them... or more generally, an affirmation that sometimes I can't imagine the reason things are done a certain way, and in those situations I should be more humble and put stuff back exactly as I found it even if it means scratching my arms up and fighting with locking pliers.

There was another recent fault I encountered with this car too: the previous owner had removed a weird device called a radio interference capacitor. Consequently, a faulty ignition coil (verified later by occasional misfire on cyl 4 that moved to cyl 5 with coil musical chairs) was creating interference that bungled PCM communication and caused all gauges to sweep when the throttle was opened. The fault was irregular and would disappear when I disconnected and reconnected the battery. The car behaved as though it was learning to run worse each time I started it, triggering the fault more consistently with acceleration.
The only reason I found it was because I completely gave up and the easiest next step was: "the service manual says this is supposed to be here. I don't know what it is, but I guess i'll try installing one."

I hope you'll forgive the preaching. I'm sharing for myself and in hopes it might trigger a lightbulb moment for you, if there's one to be triggered.

I bet the service manual would describe this fault simply as "poor fuel economy" for troubleshooting purposes, so I'm going to start digging around towards that end. I think you're heading in the right direction by testing EGR operation. I'd forgotten in my last post that you'd said the fault went away very briefly after you disconnected and cleaned the EGR. That's the biggest factor in my thinking the fault could be something else *besides the valve itself. Still best to verify that the actual components are working correctly.

I hope this super wordy post is actually helpful. Will be back soon with more targeted stuff. I remember your post about repairing something inside an ECM and thinking that was really cool, so I want to help extra.

 

Some early digging results including procedures for testing EGR stuff (hopefully makes your life easier) added below.
It seems like this car has a code for freakin' everything. Even the gas cap! It's a miracle you don't have one triggered. Everything I can think of should send a code..

One thing that may be of note. The EGR system is dependent on engine coolant temp sensor 1.. and I just realized by reading one of your recent posts that you're way ahead of me on that subject.

 

Thank you so much for that info, I’m going to try to go over this in the next couple weeks and get it sorted out. I’m also surprised I don’t have any codes at all, I’ll check back in when I find something. Stay tuned.

 

It was colder then a mofo this morning, and my EGR didn't open at all on my 25 mile commute to work, which is mostly interstate. I have the upper and half of the lower grill blocked, and intake temps were still only 5-8*F, so I think that has a lot to do with it as well.

Not sure what your temps have been locally, but I figured there is something to do with intake temps/aft and egr.

 

but when it was closed did it read egr commanded and egr error at 0 while driving? Because mine never changes ever.

 

Correct. Both were at 0. Did the same thing again this morning. I am guessing the colder temps the MAF is picking up are dictating the EGR operation.