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Discussion Starter #1
The other day I was driving on the highway I hit the brakes and realized heavy vibrations, I’m assuming I must have a warped rotor, a few minutes later I had the check engine light and vtm light come on. I checked the code it’s P0401.
I cleaned out the intake and egr valve, I cleared the code started driving but both lights came back on.
Any help here would be appreciated.


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Sounds like two problems.

The brakes pulsing (vibrations) is most likely not a literally warped rotor (they almost never actually warp). What happens is that you stop really, really hard and come to a complete stop with your foot still on the brake. At this point, the rotors may well be hot enough to glow, and the heat causes some part of the brake pad to fuse into the metal of the rotor, changing its "stickiness". Then every time that section passes between the pads under braking, you'll feel a vibration. It'll tend to dissipate over time, unless of course you do it again (and it does happen all too often in urban freeway driving).

The P401 code refers to a the EGR error (insufficient flow). The troubleshooting procedure in the manual requires the use of an HDS (Honda Diagnostic System) - if you have one of those, I'll post the procedure (if not, it would be pointless). If cleaning didn't fix it, I'd suggest it could be the EGR valve itself. It's not all that expensive, so swapping it out would be a fairly high-percentage maneuver.
 

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Discussion Starter #3
Unfortunately I don’t have an HDS. My plan is to attempt to clean it again and make sure that I didn’t miss anything. If not I’ll replace the egr. Will the check engine light go away on its own or should I clear it.



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Most emissions codes will clear themselves eventually, but often take a few driving cycles to do so. I'd recommend clearing the code (assuming you have a reader) manually if you can.
 

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The other day I was driving on the highway I hit the brakes and realized heavy vibrations, I’m assuming I must have a warped rotor, a few minutes later I had the check engine light and vtm light come on. I checked the code it’s P0401.
I cleaned out the intake and egr valve, I cleared the code started driving but both lights came back on.
Any help here would be appreciated.


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1. Do you use regular gas?
2. If yes, Time to open very top small cover with about 6/8 bolt and clean the channels. I bet all are completely clogged. Don’t forget to clean the tiny holes that goes into intake and allows circulation,
3. Good luck and let us know your findings
 

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Discussion Starter #6
I’m the 12 years that I owned the car I have only used premium gas. Never regular.

I already opened up the cover and cleaned the tiny holes and the big hole on the side. (Everything was clogged)

And I removed the egr and cleaned that also. But nothing. I probably drive about 50-60 miles since I did all that but the check engine light keeps coming back on and the vtm light also comes on but that turns off and then back on.

Might change the egr and see if that helps. But before I do that I want to take a look and make sure I didn’t miss anything when cleaning it


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I’m the 12 years that I owned the car I have only used premium gas. Never regular.

I already opened up the cover and cleaned the tiny holes and the big hole on the side. (Everything was clogged)

And I removed the egr and cleaned that also. But nothing. I probably drive about 50-60 miles since I did all that but the check engine light keeps coming back on and the vtm light also comes on but that turns off and then back on.

Might change the egr and see if that helps. But before I do that I want to take a look and make sure I didn’t miss anything when cleaning it


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Did you remove intake and cleaned? Make sure the metal gasket you put it in correct direction. It fits both directions but only one particular direction keeps the holes open. If you put wrong way then it will block all the holes, car will run with vibration and codes will show up. Also, there may be tiny slim rubber gasket that needs be in properly placed. Tell the details on what work did you perform and may be I can help but I’m not the expert.

I fill regular gas since last 5 years and no issues.
 

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Discussion Starter #8
I took the top cover off the intake and removed the egr valve... I blew carb cleaner all around and cleaned out all the gonk I also blew it down the bigger hole on the side and watch it come up through where the egr sits. I then used my compressor to make sure the holes were clear.
I then used carb cleaner on the egr.

I might have to check that I put the gasket back on correctly. I did notice there’s a piece of rubber that seemed a little flimsy. I’m attaching a pic if this can be replaced and someone knows what it’s called let me know.

As far as the gasket goes. Will I be able to notice which side is correct by seeing that the holes are showing?



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Discussion Starter #9
I opened it up again today, and everything looks clean no gonk... and the gasket was on the right way. Not really sure what else to do at this point other then changing the egr and see if that helps. Even though the cel is on the car is running fine.


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On a high-mileage car, I never feel bad "shotgunning" an item that's more or less a wear-and-tear item (like a shock, PCV valve - or EGR valve). Even if it doesn't fix the problem, it's not a bad idea to swap it out anyway.
 

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Just to be sure - did you see 6 or 8 tiny holes on the intake? Has vibration gone now that you cleaned the system? If it has then - Did you reset/clear CEL? Buy cheap Obed scanner from eBay. May be $20 or less.
Did you do any other work on car before getting this issue? I will post picture if I find mine. See the green highlighted 6 holes.
1DD7DF25-B38B-48C7-A182-C764C664C47C.jpeg
 

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Discussion Starter #12
The vibration I believe is from the rotors (3year old rotors, can’t believe they went bad so quick)

I cleaned out 6 of those little holes, I also changed the egr valve, I cleared the codes and the code hasn’t come back BUT I just checked it and I see the P0401 code pending . So I’m guessing that the check engine light will come back on.
I bought the egr from Pepboys, and I noticed the hole on the bottom is a little smaller then the original, not sure if that makes a difference or not. If this light comes back on I’ll be right back to square one. Any other suggestions.


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You need to clear the code. Buy cheap Obed scanner from eBay, for about $15 or so. It is simple to use. Vibration doesn’t come from rotor unless at the time of applying brake only. Your issue is definitely an EGR flow.

So, first time you missed to clean those 6 ports. Correct? Did vibration go away? It is very easy to make mistakes putting metal gasket wrong way. When you put back all holes must be visible after gasket is placed so it allows gas to recirculate.

Pep boys EGR should be fine. Next time take pictures of gasket in place and post it.
eBay is best source of buying brand new auto parts at cheapest.
 

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Discussion Starter #14
You need to clear the code. Buy cheap Obed scanner from eBay, for about $15 or so. It is simple to use. Vibration doesn’t come from rotor unless at the time of applying brake only. Your issue is definitely an EGR flow.
I have a scanner and I cleared the code but it continues to come back.
The vibration is only when applying the brakes that’s why I said it’s the rotors.


You need to clear the code. Buy cheap O So, first time you missed to clean those 6 ports. Correct? Did vibration go away? It is very easy to make mistakes putting metal gasket wrong way. When you put back all holes must be visible after gasket is placed so it allows gas to recirculate.
I cleaned those 6 ports the first time and I had the gasket the correct way. The second time I opened it I made sure that the gasket wasn’t covering the 6 ports.





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Discussion Starter #15
I’m going to return the egr valve tomorrow since that didn’t fix the issue. And from what I’ve read and what my mechanic told me these Egr valves rarely go bad they just need to be cleaned.
The issue must be something else since a new valve still has the check engine light turning on


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If you haven’t already, you might check the wiring and connections. There are a couple grounds in the circuit. Search the forum or google for the diagram.

Good luck!
 

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Discussion Starter #17
I’m thinking maybe I have to take the intake out and see if anything is clogged under neither.


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Discussion Starter #18
The rubber seal that’s circled in the picture looks worn and doesn’t really sit in place. Can that be causing the p0401 code? Anyone know the part number for that seal?
Thanks in advance



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Discussion Starter #20
Yes, I cleaned the channels on the intake cover, I cleaned the 6 holes on the intake, and the egr valve is cleaned.


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