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'04 S430
270 Posts
Discussion Starter · #1 ·
Last year, after a good highway run, it would clear itself two days later, and I managed to sneak it through inspection that way. The next day after getting the new inspection sticker, the CEL came on. No biggie, I knew what the issue was.

Well, now the car's CEL does not go off at all. Looked through the forums, and found what most thing the culprit may be: A clogged ERG tube.

I decided to dig into the engine a few months ago, this is what I found:

I cleared the codes - but light did not stay off for long. I kind of let it go till this week. Fixing of the clog didn't fully correct the problem. The P0400 error code kept on coming on. It bothered me that I never did fully check the functionality of the valve itself before I put it all back togther.

On the 17th I finally decided to pull it apart again and see if I could find the problem. Pulled the ERG valve off, with the tube attached and blew into the tube to see if it had a good seal. I could blow through a little, but when I opened the valve manually, I could blow though a whole bunch easier. However, I was afraid that I put a whole in the accordion part of the EGR tube when I removed it the first time, and I don't think I did, the air was leaking through were it was suppossed to go though on the valve.

Next I checked the vacuum hoses - I had already replaced several of the hoses because they have become stiff and brittle, and I thought I found my issue. I think the first time I pulled the valve off, I did not disconnect the vacuum hose properly from the engine, and ripped a small hole in it.

Went to Auto Zone, and for $0.96 I got a longer replacement hose. Not quite the right size, but I put a zip tie on it to hold in in place. Put it all back together, reset the code, but the code came back again.

Here is a picture of the valve with the way too long vacuum hose.

On the 18th, I pulled the EGR valve off last night. Sprayed the heck out of it with some SeaFoam deep penetration stuff - smelled like WD-40. Says it cleans and lubricates.

Anyways - sprayed it all over the valve, tested the vacuum release actuater to make sure it worked, and it did. Vacuum tested it and the valve did move up and down. I zip tied the new vacuum hose in place on both sides this time, and zip tied the electrical connection to the vacuum release (I couldn't get the locking mechanism on it to work right due to breaking a little edge off the connection). Reset the code, but the light came back on the same day.

Is the valve good if it not fully sealing? I can blow through the EGR tube and, although it is restrictive, I am able to blow through the EGR Valve.

Also - anybody have any other ideas on what could be done to clear this code?
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