I also read:

way the ECM determines if the flow is too low is by looking at the O2 sensor for changes when the EGR valve is open.

And:

Try removing and cleaning the EGR valve again. It's likely that the valve is gummed up. Before re-installing the valve, spray some gumout down in the manifold passages, then start the engine with the valve still off. This should help blow out some more of the deposits remaining in the exhaust manifold


Not sure of either of these things make sense.

 

Thoughts?

 

There’s a second part to the diagnostic test where you connect battery voltage to a couple of pins on the EGR valve. My understanding is…This forces the EGR valve to be open at idle which would allow airflow through the EGR passage and would cause a rough idle; if, indeed, the passage was unobstructed, and there was adequate airflow.

if it’s obstructed, the egr valve will have no effect and idle will be normal.

 

Went out for lunch and lots of questions and comments. I try to get to what i can answer. I know that it is frustrating but you get the best help when everyone is on the same page and knows what you have read and what you have tried. People assume someone with a problem will have downloaded the manual, read it, and tried the published "solutions" but still are having issues. Not trying to chastise; just trying to get you up to speed.

1. Guess this clears the pcm better than clicking "erase codes" on the engine light reader? By disconnecting the battery for a while it will clear the PCM memory, erasing codes erases the codes but doesn't clear all the memory.

2. Is egr valve position sensor a separate part from egr valve? On some cars it is separate but on the Acura's I believe that the top portion where you plug in the 6 position connector that is the sensor, the valve being attached to the bottom.

3.... way the ECM determines if the flow is too low is by looking at the O2 sensor for changes when the EGR valve is open. Try removing and cleaning the EGR valve again. It's likely that the valve is gummed up. Before re-installing the valve, spray some gumout down in the manifold passages, then start the engine with the valve still off. This should help blow out some more of the deposits remaining in the exhaust manifold . These both make sense. Do you have and OBDII reader that shows the 02 sensor readings, short term and long term fuel trim? The PCM can have a failure on one set of outputs, I.E. The PCM can function for most things but be bad for just one function. This is NOT saying your PCM is bad.

4. At this point, maybe I need to purchase NEW OEM HONDA egr valve and map sensor. thats about $325.At this point you already swapped in another EGR valve and another MAP sensor. Unless the sensor was bad or the EGR valve was stuck I don't think these are your issue.

5. Not sure about the Valvoline, It is a commercial. Seems much like Seafoam. It may or may not work.

6. Find the specifics on what Whitetiger5 said and try it if you are comfortable with doing the procedure. Make sure you understand which pins are the correct ones and how much voltage to apply. The unit normally operates on 1.2v from what I can see.

 

Thank you, kindly!

I disconnected battery and had the connectors touch each other for 2 hours. Drove car. Within 15 miles, the code returned.

Maybe I didn't clean the egr port as well as I could have. Just because the top of the port on the intake was clear, and the opening where the egr valve sits was clear, doesnt mean the clog isn't in the "elbow" or some other spot. Ideally I would like to run a pipe cleaner or something similar down into the egr port at the intake and have it come out the other end (opening where thr egr valve sits on top of).

I will try and do the voltage check which you explained perfectly.

Not sure what type of reader I have. I think it's the cheap autozone model. Not sure what it does or doesnt do.

Will have to take photos.

Thank you very much!!!!

 

The EGR vale does have ability to provide feedback on it's position (how open vs how closed it is). if it fails to report back this information then there would be another error P1498.

Domenic, theres another test (other than resetting the PCM and decelerating from 55 mph to observe the EGR doing it's job; it's in the part below; did you give that a shot?

everything I am reading so far continues to point to the EGR passage being obstructed in some way.

btw...did you check that the upper valve cover gasket was placed in the correct orientation? not upside down?

 

Will give it another cleaning. Amazon cart is ready.

 

@Domenic Ricci May want to use the type of tool shown in this video....the clip I attached below describes the area that I would check at the 4:42 mark. you may need to attack that passage from both directions.

additionally...there was a member who found their catalytic converter failed and the chunks of the catalyst had made their way up through the EGR passage on the other side of that valve....may want to check that passage as well a cleaner should freely go down through that side as well (I wouldn't spray anything down that other side though)

 

Great video. I absolutely want to get something to go through the entire passage. In one end and out the other. Speedo cable action! Speedometer cable? Guess I have to find it on Amazon.
gotta think the clog is in the 90 degree turn elbow. I was able to clean the other areas, but I have to get to that hiding spot.

 

What side should I spray and what side should I not spray? Are you talking about the openings where the valve sits down? One circle opening and one rectangle opening?

 

exactly. I the side that leads to to the exhaust manifold (I believe circular) I wouldn't spray anything or do much cleaning for that matter. just check to make sure there are no obstructions there.

please disregard what I mentioned about catalyst material being present there...I saw that in another thread and turns out it was for the 3rd gen, which has catalytic converters much more upstream. s

 

Full disclosure: during previous cleaning attempts last week, I did spray ALOT of cleaner down into the round opening.........

Also, I found bicycle brake cable on Amazon that may be good to use, similiar to the speedo line used in video.

In one end and out the other. Back and forth action. Turning with drill. New pipe cleaners. Previous cleanings did not do that. I just cleaned the openings and sprayed alot of cleaner. Next cleaning will mimic what was showed in that video. Thanks.

 

Also, I will be sure to clean the throttle body plate and area.

should I also use the cleaner and spray into throttle body mouth with car on and revved at 2.5k rpms? Is type of cleaning helpful? Any tips on how to best perform this type of cleaning. I have only attempted this once in past.

 

I've never cleaned a fuel injected vehicle by spraying anything into the throttle body.

I'm not sure there's any benefit to cleaning the throttle body...maybe the IACV...but I'd suggest to leave those to minimize the number of variables for the moment.

 

When you clean the throttle body itself you can do it when you have it disconnected or running using carb cleaner but if you are thinking of the Valvoline stuff you mentioned earlier that is a different case. Personally when I want to clean the throttle body I take it off and clean it with carb cleaner. The car running cleaning sucks the fluid down into the cylinders etc. Many require changing the oil afterward. The products like the one you mentioned and Seafoam have people who believe in them and some whom don't. I would avoid these products, at least until you fix the current situation without introducing a new factor, just as Whitetiger5 suggested.

 

To do the job properly, which I did myself, you get a new intake manifold upper top plate gasket, you pull that off, you cleanout all the EGR passages in the intake manfiold/plate. You then pull the EGR valve and clean everything from the intake manifold to the EGR valve, and likewise you do it from the EGR valve to the exhaust manifold. Even if a bunch of carbin breaks off, the engine isn't running so anything that makes it to the catalytic converter should burn off once the car is running without issue.

I did this whole procedure, replaced the EGR valve and the car has been running perfectly since.

Trying to use sprays is a GIANT waste of time... At that mileage (mine was around 232k miles) there is NOTHING the "spray into the intake while the engine is running" do for EGR deposits.

I did mine as part of a set of new plugs, new coils, setting valve lash, new filters, etc, and everything else associated with a good ol-fashioned "tune-up".

 

Thank you guys! Very much appreciated.

Going to do the cleaning this weekend. I have all the cool tools now. Cleaner. Compressed air. Multiple sized straw cleaners. Pipe cleaners. Bicycle brake cable to fish from one end to another. Drill. You name it, I have it.

the oem egr valve that I purchased at junk yard, appears to have the gasket stuck/affixed to it. Not sure I can remove. It almost looks like its part of the egr valve now. Just hoping between that and the new egr valve gasket, that I don't cause a vacuum leak. Maybe I should leave new gasket off ?

 

Not telling you to do this for your EGR valve but the best gasket scraper I have had is this one.

One method of removing old gaskets are to let it soak in wd-40 and then use a appropriate hammer to tap on it. What I mean by appropriate is the metal of the hammer has to be softer than the metal that the gasket material is stuck on; this is VERY important as a denser metal will deform the mating surface. I,e if the gasket is stuck to steel you can use copper, brass, or aluminum but not steel. You can also use a hard plastic hammer. Of course, I am referring to the head of the hammer not the handle. After using the hammer (if needed) you can carefully use a scrapper or razor blade. Do not dig into the metal surface.

 

Latest update on egr passage cleaning. Also cleaned the egr valve again.

Cleaned with pipe cleaners. Wire brushes. Straw brushes. Toothbrushes. Up and down. I gotta say, not much gunk or grime on the brushes after cleaning. One of the brush cleaners almost got stuck. Had to rely on a little luck to get the brush to come out (I inserted it down the passage from the top intake and when i went to pull it out and up, it wouldnt budge. Had an "oh shit" moment). Couldnt get a brake cable to go in one end and out the other. Could only go down or up as far as I could. Used pb blaster. 5 cans of cleaner. 2 cans of compressed air. A vacuum. If the code come back on I guess it has to go to acura service. I have seen gunned and dirty ports on YouTube. My port is not gunked up. I know I'm not a professional, but I'm confident the port is clear. Maybe it's exhaust related.

Hooked everything back up. Drove car. Runs perfect. Strong. Slight (very slight) chugging noise from under hood but that could be me listening for things that aren't there. Idles perfectly.

We will see. I anticipate the check engine light to come on on way to casino tonight. Bingo awaits!!

 

Oh speaking of not being a professional - I think the little black plastic straw flew down into the round hole on the egr housing. The round hole that goes to exhaust. Maybe explains the light white smoke? Hopefully it burns off. Don't laugh. Thanks.

 

Your aren't supposed to drop stuff into the engine, you are supposed to lose the 10mm socket.

 

Car runs well. Engine light and TCS light back on. Same insufficient flow. Kinda getting on my damn nerves now. I cleaned the fine port 4 times. Must have used 200 cans of cleaner. Brush and all kinds of tools.
Even after one mechanic said it isn't clogged or blocked. He said needs egr valve or pcu. If it needed a valve it would throw a different code. He said not always. Ok so now I'm supposed to buy a $300 valve only for the light to come back on? Or take it Acura and spend $500 for them to clean the port and install new egr valve. I not sure what to do. I should have taken a video, I could have shown how I cleaned it and that it appears clear to me. Only thing I didn't do was fish something thru one end and out the other or have an air line / air gun to power blast air through tht damn thing. Ughhhhh.

 

Same mechanic who said to replace egr valve - told me the brand new duralast valve from autozone is crap. Even though it is brand new. Said has to be honda. So I went to junkyard and got 2 oem valves. Still the same code. So a few valves and 4 cleanings. Has to be something else. But no other codes. And bad pcm should make other weird codes appear or present other issues. God dang car runs perfectly. I could ignore the light, but with the light on it won't pass inspection/ registration.

 

And if I need an ecu/pcu, how do I know which is correct?
ECU 37820-P8E-A53 I assume. Versus the A52.
But there is an L53 for CA emissions. I am not sure how to tell if i need CA or Federal emmissions.
are they "plug and play" or is there programming ($150) as Acura told me?

My thought here is, I buy new egr valve from honda. I install. Light comes on, I drop car at mechanic. Tell him it has new honda egr valve and clean port. Tell him I not picking car up until code goes away. He can keep it for week for all I care. That's what I did last time when I was in IACV code hell. (Turned out, needed Honda IACV....NO other brand would work).

 

Domenic, Sorry to hear the problem did not go away. Out of curiosity how long after you clear the code does it take to come back? Is there enough time for you to clear the code at an inspection station parking lot and then have then do the inspection before the code comes back?

I have tried multiple IACV (i know it is not your current problem) manufacturers and none perform as well as the OEM. SMP's did allow the car to run ok but not the same. I took several apart and OEM was much better built. It could be the same for the EGR valve but I don't recall seeing anyone post a bunch of problems. CA emissions spec are tighter than federal, I have no idea about the ECU. From what I have seen from some schematics you can have just one function go to crap without affecting the other functions.

 

I have the Standard Motor Products EGR valve installed on my car...I updated it when my original problem was an ignition coil, so both original and this are working identically.

Amazon's current price is slightly better considering shipping.

 

Hi Jon! Appreciate you!
The light comes back on quickly. Faster than it takes for the catalysts system and evap system to,finish its readings. Erasing the code wont work because the DMV will check to ensure all systems were read and without error.

I think I can check on door panel or under hood as to whether or not car is CA emmisions or not. This will help me determine what pcu to purchase from ebay, if i go this route.
thank you for letting me know that the pcu could potentially be the issue, even if other weird issues or check engine lights aren't present.

 

I think standard motor works very well, but this car is a pia and seems to only function with oem. I guess I have to bite the bullet and purchase the honda oem egr valve. Though remember, I am not convinced the valve is the issue. As I believe this would provide a different egr engine light code. And considering I have tried 2 used junkyard oem egr valves and light still comes on.......

Maybe I need one of those thin air guns / air hose lines, and blow the heck out of the port. Idk. Port looks clean as a whistle. But issue could be where the eye cant see. The egr passage itself can't be replaced, right? It's part of the actual intake?

 

The issue could be the EGR valve...even the manual states to replace it if the very same error persists (see post 36 above).

I was just suggesting to try the SMP solution first or even try and return/exchange your duralast unit. it certainly is possible to have two failed units in your hand.

Dom, did you try the troubleshooting above in post 46 where you force the EGR open? That will tell you if your port is clogged still...clogged port: no rough idle at start with egr forced open, unclogged--> rough at idle with egr forced open.

 

regarding post 46
Thank you! Do I need a special tool? What would that tool be? Sorry for my ignorance....

 

hi, there are a few ways you can do it...if you don't want to buy tools, use a jumper wire or the appropriate tool would be an automotive circuit tester.

 

Did you ever download the manual? It is a large file but the information inside is priceless.
Also what state are you in? That inspection sounds more intense than I have ever heard. In CA they look at the CEL and may even hook up to the OBDII but they don't exercise each system I don't know how they would even do that.. They let the car warm up and check the emissions. I even had one check the engine for visible modifications.

 

I think he is referring to the Smog Check Station? They willcheck the PCM for smog readiness.

Dom, I'm looking around at other forums related to your P0401 code...definitely want to test where you force the valve open by applying voltage appropriately. this will rule out if you really cleaned it properly.

Also...did you return or exchange the duralast EGR? Might be good to do if it's not too late.

 

5hank you! I will purchase the auto circuit tester and diagnose as you instruvted. Easy instructions, even for me.
yep, smog check here in Nevada. Though I will say, sometimes it depends on the inspector.

 

Something like?

 

Whitetiger5, When you say they will test the PCM for smog readiness, what does that mean? Do you know what they are looking for and how the check is done? My understanding is once the code is cleared there is no permanent storage of codes. I am confused on how they find a problem if the codes are gone.

 

If that port is still clogged, I need to get my hands on one of these!!

 

Hi Jon, I was referring to the feature where the PCM needs to operate first in certain conditions before it can confirm that it is "ready." Typically happens when the battery is disconnected for long periods of time, or whenever DTC's are cleared.

Precautions to prevent someone from resetting the PCM just before the get the car smogged.

It doesn't say there was a P0401, but more so that it hasn't been operated enough to confirm that there isn't a problem so don't test yet.

 

Dom...my apologies. I was thinking of the wrong name. Test Probe is what you are looking for. it's close to the top item. allows you to connect one set of connections to the battery, and the other set to the component you are testing, with safety (the test probe has internals to protect against high current/shorting where a plain old jumper wire does not).


They can get pricey, but honestly I can count on my hand how many times I've needed to use one so the item on the top there is a great choice.

 

Thank you. If I read the instructions correctly, I will need to connect test probe to positive to one of the power supply pins. And do the same for negative to other power supply pin?