CEL AirFlow
Thanks
B. From whom did you purchase the maf that has only lasted a few months?
C. If you bought it off fleabay or at the auto parts store you have your answer.
D. Report back when you have the codes.
I think I will invest in a code reader of my own.

P0400 is not egr it is egr flow and originates from the intake towards the egr valve. I have an easy way to clean,the harder way is to pull the metal tube fronm the egr to the intake and clean all the gunk carbon from its insides.
Diy is on www.benzworld.org w210 diy forum.
CRC brand MAF cleaner is your friend in dissolving the carbon goo that blocks the egr tube.
Seafoam has been recommended as a good fuel system cleaner. Are you asking in general, or if that will fix the cause of your CEL?
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I talked to my wife this morning and the CEL has gone out. She drove 190 miles yesterday so maybe some got blown out . I am still going to take the EGR apart and clean the tube out. And also put in a new radiator. Its leaking. New one ordered . Thanks for all the help.
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However there is a very well respected member of this forum who really likes and uses Seafoam and I have a lot of respect for anything he says.
Also this is just a thought so dont think I am a dummy. Could one not modify the tube by cutting the middle out of it and install a connection and then remove the hose and clean it after removing the piece out. You could cut it before it goes into the engine and remove it there and the nut where it attaches to EGR valve. Seems like it would be a bit quicker to do that than to remove the whole thing to clean it out. OR does the carbon need to be removed from the tube after it is taken out . Seems to me it would not matter. It would get burned up in the engine and be gone. Any way just a thought.

I went down to the Benz dealer to get the gasket and screws for the tube and talked with a mechanic and he said he wouldnt advise cleaning the tube without removing it completely. He said the carbon falling down in the engine could cause some bad things to happen. He also said it could be cleaned witout removing it but it should be removed.
Last edited by earld; May 30, 2012 at 02:04 PM.



