Opo

Hello all,

I just bought this car and it threw some codes under moderate acceleration, the codes were

P0404
P0401

So I did some searching on these forums and I removed the EGR valve and cleaned the inside of it with throttle body cleaner until clear fluid came out and no more brown fluid was coming out of it, dried it out in front of a fan and re-installed it.

After some more driving around the car threw a code again, this time it was only one code:

P0401

And I'm now looking for some more direction as to what I should try next to fix this code from coming back again.

The car is stock other than a short RAM intake pipe with K&N air filter and an aftermarket muffler.

Thanks guys.

It Wasn't Me

Did you also clean the EGR port on the intake manifold, or just the EGR valve?

If you did, you might just need a new EGR valve.

Opo

No I didn't clean the ports underneath the EGR valve cuz I didn't know if it was safe to be spraying the cleaner in there, I can clean them today though and see if the code stays away after that

Opo

Okay so I took the EGR valve off again and cleaned inside the ports that it goes over top of with throttle body cleaner and then when I was running the engine afterwards it blew out quite a bit of white smoke so I know it was cleaning out the carbon deposits in from where I was cleaning which was good news.

The check engine light stayed off for about a day and a half and now its back on again, so what should I look at next? just replace the EGR valve? or is there something else I could clean that would be causing the code.

The code is P0401 btw the low EGR flow code.

The car only has 116 000 KM on it btw.

Charlies Auto

Hi. P0401 is insufficient lift of EGR valve.
I want you recheck EGR clean as followings.
remove EGR valve. Remove air filter cover and air filter. depress accelerator pedal (by your friend or pull throttle cable).
Use compressed air to a hole of EGR port(close to engine head is the one) . Listen air sound from throttle body. If you head good sound, the port is cleaned well.
Now you need new EGR valve.You do not need to put Honda OEM(too much).
Remove gasket well as it will be stays on top of head(usually).
You may try to clean EGR valve with pushing bottom pin by hand and spraying intake cleaner, but most of time, EGR is damaged inside.
Let me know the result.
Also remember. The code is usually takes 2-3 days as PCM/ECM must confirm for 2 drive cycle.

It Wasn't Me

P0401 is EGR Insufficient Flow Detection

P0404 is EGR Valve Insufficient Lift


To Recheck for P0401, you reset the ECU - then go for a test-drive under the following conditions.

- Without any electrical load. (nothing on but the car)
- Decelerate from 55 MPH (88 kmh) for at least 5 seconds.

- Check for temporary DTC P0401





To recheck for P0404, you first reset the ECU - then proceed as follows.

- Start the engine, and hold it at 3,000 RPM without load (in park or neutral) until the radiator fan comes on.
- Test-drive the car for about 10 minutes, while trying to keep the RPM in the range of 1,700 - 2,500.
- Check for temporary DTC P0404



Good call on this. I have heard of those passages being clogged with buildup. (requires a bit of work to thoroughly clean)

Opo

Okay so I took of the ram air intake piping so that the throttle body was exposed and took off the EGR valve so I could get to the ports and I had my girlfriend listen and feel for air coming out of the throttle body while she held it open and while I used a compressor to spray air through the EGR port closer to the head and she didn't hear or feel any air.... And when I was trying to do it by myself I couldn't hear any air coming through either. I tried spraying the other port too just in case I read what you said wrong and still nothing there either..

The only code that keeps coming back now is P0401, the insufficient flow one.

So I guess I need to clean all those internal passageways now? How the hell do I do that? lol

Thanks guys I greatly appreciate the fast help especially because I have to take the car for emissions test in the next 8 days. I'm surprised there's no FAQ for cleaning the EGR passageways.

singlecammin

oops....

lazlong

This is becoming a common problem with the D17's. I've seen people take off the intake and clean the passage behind it. Probably wouldn't hurt to clean the throttlebody and intake while you're at it.

* Don't fix it and drive straight to the inspection- guaranteed not to pass. You have to drive it around until the readiness codes are set before it will pass (just try to cover as many conditions as possible).

Opo

yeah i found some videos on youtube of people cleaning the EGR passageways on other D-series but their intake manifolds were completely different designs from the D17A2.

the D17A2 has a plastic intake manifold and is pretty damn small, I'm thinking I'm going to use seafoam through the brake booster hose to clean out the insides of the intake system, it looks like a nightmare to take apart and clean while its off the car.

lazlong

^^ Yeah, D17's are different from other D series. It's pretty much the same procedure tho.

Opo

Okay so the plot thickens some more....

I used seafoam introduced through the brake booster hose to clean out inside the intake manifold etc. And cleared all the codes and the car is running good. AND it passed etest with flying colours! And then a day later code P0401 insufficient EGR flow came back again! Wtf... So is there anything else I can try other than taking the intake manifold right off and manually cleaning the whole damn thing to stop this code from coming back?

silron

i am dealing with same problem,got new EGR,cleaned ports,still p0401.next week i am going to removed intake manifold and do a major cleaning.

see if this help

DTC P0401: EGR Insufficient Flow

Reset the ECM/PCM (see page 11-4).
Test-drive under the following conditions.
Without any electrical load.
Decelerate from 88 km/h (55 mph) for at least 5 seconds.
Check the Temporary DTC with scan tool.
Is Temporary DTC P0401 indicated?

YES
- Clean the intake manifold EGR port with carburettor cleaner. Clean the passage inside the EGR valve with carburettor cleaner or replace the EGR valve.

NO
- Intermittent failure, go to step 4.



Turn the ignition switch OFF.
Disconnect the EGR valve 6P connector.
Connect the battery positive terminal to EGR valve connector terminal No. 4.

EGR VALVE 6P CONNECTOR



Terminal side of male terminals

Start the engine and let it idle, then connect the battery negative to terminal No. 6.
Did the engine stall or run rough?

YES
- Intermittent failure, system is OK at this time.

NO
- Clean the intake manifold EGR port with carburettor cleaner. Clean the passage inside the EGR valve with carburettor cleaner or replace the EGR valve.

paulo500

Hey Opo, did you end up fixing your p0401 issue?
I too have the same error code in my 02 Acura 1.7EL. I've cleaned the EGR valve twice with TB cleaner but that didnt do anything. I also sprayed TB cleaner down the ports where the EGR valve sits, but that didnt do anything either. I've seen alot of tutorials online about how to gain access to the intake manifold and cleaning out all the ports, but nothing for our D17A2 engine.

I've got an emissions test coming up too, but im assuming it wont pass if the p0401 is on. I'll probably just reset it as im in the parking lot about to get the test done.