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About 13 months and 7500 miles ago, my mechanic replaced the EGR Valve and Tube and cleaned the intake to solve the low airflow problem. Now I'm again getting an insufficient flow warning with my check engine light (code P0401). I noticed the light shortly after rapidly accelerating because of a short merge lane in temperatures around 90 degrees.

My main question is: Is there anything else that wasn't replaced or cleaned last year that could be causing the problem?

Also, I know Accords like mine have problems with buildup in the EGR system. But has anyone else experienced repeat problems with the EGR system within such a short timeframe?

SAG
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3 Answers3

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If this is the V6 Accord, it very well could be an issue with carbon buildup again. It seems there was a tech bulletin which was issued by Honda about it for the 98-01 Accord and 99-02 Odyssey.

I found a pretty write-up of how to get it really cleaned up, as getting it into a good state is quite a bit of a job. Here is where the write-up can be found with pictures. Here is the basic write-up pulled from that website:

You will need; wire brush, some carb cleaner or brake cleaner, a shop vac, new EGR gasket $1-$2 and new EGR chamber gasket $32.00 from Honda.

  1. Remove the fuel rail with the injectors intact if possible. (Do it slow and gentle)
  2. Unbolt the EGR valve.
  3. Unbolt the EGR chamber underneath the fuel, that is bolted on to the intake manifold.
  4. Soak the EGR chamber with a cleaner and scrub the hell out of it, this took me a while as you can see how dirty it was. I mean it was hard as a rock at some spots.
  5. Use the shop vac to suck the carbon build up as you break it away on the intake manifold.
Pᴀᴜʟsᴛᴇʀ2
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Most people just clean the EGR port with a small drill and think they are done. Just inside where the throttle body mounts They are 2 side passages that are often overlooked. I had to bend a wire and dig them out. They were stopped up solid. I also took a pressure washer to the plenum. Lots of gunk and carbon came out. Hope this helps someone.

Gene

Gene clark
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A properly done repair for this should last for at least five years, repeats are rare, and I have done a lot of these.

A repeat plugging is most likely due to poor cleaning the first time. If the updated tube was installed and it was properly cleaned consider these possibility's. 1) Excess oil getting into the intake from the PCV system, or other causes of oil consumption. 2) Poor fuel that does not have good cleaners. 3) Unusual driving habits, especially short trips. 4) The EGR valve is sticking closed, but this should set a different code. All rare but possible.

Was the update tube really installed? It requires special tools, we see this left out sometimes. This tube really does help the carbon buildup. If this car is in my service bay this is the first thing I would check

By the way the EGR valve does not affect the plugging, we rarely replace them after the first updated one is installed.

Fred Wilson
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