burnhamr

I am new to the forum but have some help for others and have some questions. I just recently received the infamous P0401 code for the EGR valve and then the Insufficient flow. I replaced the EGR valve and the Ck engine Light came back on. I then took off the top of the Intake manifold and cleaned the port. It was very clogged. After that no more Check engine light. I then was good to go except I noticed that the engine would now surge at around 1500 to 2500 rpm's, like it was missing. I thought well lets do a maintenance kit, Plugs, rotor, cap, wires, PCV, and ran injector cleaner through the fuel. Still same issue. Does anyone know what might cause this? Any help would be greatly appreciated car has 163K. Surging started as soon as EGR port was cleaned out.

AccordVT

There may have been some debris lodged in the IACV (Idle Air Control Valve). Clean it out with carb and choke cleaner, check the wiring. Pirated air will also cause the IACV to tweak, check for vacuum leaks.

Remiss

true that...i would start by checking the IACV...also check your vacume hoses to make sure there isnt any that might have been unplugged

92civlude

Maybe the upper plenum gasket is torn. check with carb cleaner.

burnhamr

The car Idles fine it just acts like it is missing at the soft RPM range....1500 -2500 when it is in 4th or 5th gear (manual Trans). Also the upper gasket is a metal gasket on the intake. I did not remove the intake completely to do the cleaning. I have checked and rechecked the vacuum lines multiple times. I also checked the wiring but will do that again.

92civlude

What I mean by "upper plenum" is your top of the intake that you removed. Hey, it might be normal EGR operation! You got used to driving around with a plugged system for so long, and now youre not used to it. If it was a misfire, you would get a misfire code FO SHO

burnhamr

Intersting that you say that. I sprayed carb cleaner on all the gasket areas. No issue. I unpluged the EGR and it went away. I put my old EGR back (I have a new one that was on it) on that I had cleaned up and the problem came back. No, codes set. Now I am wondering if it is what I read on another thread. That was the additional exhaust is causing a (flameout) at the injector. This happens when the injectors are partially clogged or so he said. I really need to get this resolved. Any thought on this??

92civlude

Never heard of that. But anything is possible. I do know the fuel pressure regulators go out on this model quite frequently. maybe your is stuck on the lean side. But you would think the ECU would trip a fuel trim code. possible clogged injectors or stuck fuel pressure regulator. Let us know what fixes it!

burnhamr

The flameout sounds funky to me as well. I will look into the fuel pressure regulator. I have the new EGR back on and have looked at the fusses..I am grasping at straws. I will inform when I figure this mess out. Still no codes set...The engine practicly shutdown when I had the old EGR Valve on..shut down and restarted..and seemed sluggish..I am lost.

sublime423

sounds like that guy was thinking......

If you can't astonish them with the truth, baffle them with bullshit!!

92civlude

lol! Big words work too! HA

burnhamr

OK, I used some carb cleaner last night and blew quite a bit through the throttle body intake. I thought maybe those injecjors could use a heavier dose. It seems to be working a little better. I also unplugged all of the electrical sensor connections. Did them individually and then plugged them back in. Of course the car ran terrible and I had to reset the codes. I am now running a second tank of fuel through with Chevrons Techron cleaner. I will let you know how it worked or if it did.

sidemouzer

I am getting ready to clean out my EGR system as well. Have had the light on for several thousand miles and it's time to get it done. I'm curious to see if you got this resolved in case I run into the same situation. My car is almost identical... 1999 Accord EX, 161k, manual.

vinnyg

I just finally broke down to clean EGR Port. Disconnect all vacuum hoses, water hoses and electrical to top plenum. Plenum is connected to throttle body and top of intake mfld. The hardest part was getting the water hose disconnected on the back side of plenum. Car has about 200K miles and hoses were very tight and hard to remove. I used needle nose pliers and flathead screwdriver to ease off old hoses. I would get new vacuum hoses ahead of time so you could just change out while doing this job. Remove the plenum and trottle body together from intake mfld.

Remove EGR Valve and inspect ports. Mine were partly plugged. Take EGR valve and bench test electrical while off engine. Check Ohms on top plugs, from 1&2 and 1&3. Bottom 2 are numbered 4 and 6 looking at plug 4 on left. You can test valve with #4 to positive battery and then #6 to neg ground. Valve should open when connected. Open and close several times to check. The top pins #1,#2,#3 should read low ohms 1-4 between them and will vary as the different amount of valve position is opened or closed. Shop manual has details. If electrical test pass, soak valve portion in carb cleaner while working on EGR ports on engine.

Dissolve EGR port with carb cleaner; I did not have a cleaning brush, late last night, so I cut a heavy coat hanger wire and bent to push through port. Round cleaning brushes would be great to have for this. Gun cleaning brushes should work also. Soaked EGR port from top of plenum down to the EGR location and from EGR back to engine with cleaner. I filled ports up. Scraped inside of ports to remove loosened deposits then used hand vacuum pump to suck cleaner back out. Repeated soaking, scrubbing and removing with vacuum pump until cleaner was not dirty looking. Of course I plugged hose several times with carbon while removing liquid. I did this 3 times. Also inserted cloth rag into port to absorb remaining cleaner.

Once all liquid absorbed and removed and DRY; I used a wet/dry shop vac to pull any remaining carbon and small drops of liquid out. DANGER BEWARE DO NOT vacuum LIQUID with shop vac as a fire could occur with vapors and electrical sparks from the vacuum motor. That is why you use the hand vacuum pump to remove most of liquid. Course you could use compressed air to blow out, but would make mess all over engine and yourself unless you cover port with rags.

So I dried out best I could with no visible liquid cleaner showing up on paper towel. (Be careful putting paper into ports and falling apart inside the port when trying to remove while soaked with liquid. I learned the hard way and it took extra time to remove pieces of wet paper.) So use cloth rags first to absorb most of liquid and then paper 2nd to absorb the remaining residue, then shop/vac or air.

Since there is only 1 EGR port on this engine, it is easy to get to and clean. No boring out of plugs etc.like older cars. I did not remove intake mfld from engine to clean this. This took me about 3 hrs to clean and put back together. Cleaning took about 30 min with soaking, scrubbing. This was first time doing this so I was not familiar with job. Next time, hope I never have to, should take only half of time. Reset the engine light and you should have no EGR codes now.

Problems: Could not get new plenum gasket at local Autozone, O'Riely's, Honda shop closed, after 7pm. They would have to order. Removing water hose on back side of plenum was not easy.
Solution: Get plenum gasket and new EGR gasket ahead of time. Get new vacuum hoses so you can cut to length, assorted round wire brushes to insert in port to clean, cheap plastic brush bristles will melt with cleaner but may last long enough for this job. 2 cans of Carb Cleaner, hand vacuum pump like you use for brake jobs or a vacuum bulb to remove liquid, compressed air in a can if you do not have air compressor.

Do Not buy new EGR valve unless you have verified you ports are cleaned and tests on EGR valve with engine running indicate valve not opening. They normally are not the problem.

Hope this information helps remove the EGR Codes.

Some photos of before and after opening intake plenum in Photo Album. EGR port was plugged solid.

See link: https://honda-tech.com/album.php?albumid=35260

crashingbore

I don't see the link to pictures. Would you mind adding it, please? I need to try cleaning my accord's egr port.

crashingbore

vinnyg, the link is not working. it redirects to icloud, and says mobileme is closed.

vinnyg

Added photos to Album on this forum, see this link: https://honda-tech.com/album.php?albumid=35260


Hope that helps.

CptRedfox

It seems like no one is alluding to having this issue, so maybe i'm missing something really simple.... but how do you get the EGR valve off??? To elaborate, the issue i'm having is that the top rim of the egr valve sticks out over the 2 bolts, so i can't get a straight socket and extension bar down to them. I tried using the same extension bar and a swivel socket, but the clearances wouldn't work for that either. I flat crescent wrench won't fit. But no one else is saying anything about not being able to get it off, so please help - what do i use to get the 2 bolts undone?

MAD_MIKE

Should be easy enough. Move the vacuum hoses out of your way if that's what's blocking you. If your ratchet set is not giving you enough room move down to the 1/4" drive size for better clearance.

CptRedfox

I agree, it should be easy enough. But it isnt. The lip of the EGr overhangs the nut about 1/2" at abouy 3" above the nut so that a socket on an extension bar arrives at the nut at about a 25° angle on mine. It isn't a smaller socket sitaution, it's the angle. It's the angle that's giving me troubles, I don't have a tool that can hit it including my swivel socket set.

MAD_MIKE

You won't clear it with a 3" extension, use at least a 6" to allow a good swing with the ratchet. I don't see why you would have a problem, even with the angle it's not that tight of a nut. Just make sure to use a 6 point socket so as not to round off the nut. I really don't recall it being a problem, just unbolted mine to clean out the EGR system don't recall any issues removing it.

CptRedfox

Im using a 12" extension bar. Can you post a picture of yours? I'm starting to wonder if mine is installed wrong or someone previous put the wrong part on.

MAD_MIKE

I have a '95, '98-02 is similar with a larger EGR valve body but I thought it has a smaller diameter on it rather than the diaphragm on 90-97s.
Can you put the socket on first and then install the U-joint/extension/ratchet after. IIRC the stud through the nut is *just* tall enough that it intrudes into the 3/8" square drive hole of the socket. As long as the 3/8" drive is not slipping you should be able to break it free.

Alvin c

Need help I have similar problem now idling went mad after cleaning the egr passage and taking the manifold to clean the inside with carb cleaner