earld

My wifes '01 E430 CEL light came on this afternoon. Went to parts store and it was decoded as Mass Airflow Sensor.. I changed it a few months ago when the light came on then. Not to be wrong I took the new one out and cleaned it and re installed it. The CEL light is still on. How do I get it to go off ? Or does it do it on its on ?
Thanks

ohlord

or codes?
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.

earld

Surprise Surprise.. went back to Autozone this morning to get the code read again. Different person this time . Code is 0400 EGR . Person that did it last night must have been inexperienced. But I went to a garage also and they read the same thing. So, I am sure its the EGR . I will take those off and clean them out and see if that works if not then I will get some new ones. As far as I know they have never been removed or replaced . Car has 178K miles on it.
I think I will invest in a code reader of my own.

ohlord

59 buck obd2 scanner. You can get a 20% off coupon out of popular hot roddding and field and stream. Just tear it out at the library
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.

earld

Wife is out of town the rest of the week. I will take it apart next week and get back to you . Thanks a lot for all the info. Earl

earld

Was told today that the "SeaFoam" cleaner will work when put in gas tank. Any truth to that?

Musikmann

If cleaning the MAF fixed the problem then the CEL will go off on it's own after a few drive cycles, or you can erase the underlying code(s) with any of the OBD2 scanners.

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?

earld

I was aware Seafoam wouldnt fix the CEL. I was told it would help eliminate the carbon build up in the engine. May have been a sales ploy to get me to buy the Seafoam. I guess if it was it worked.
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.

Musikmann

I have never used Seafoam mostly because it is not on the MB approved fuel additive list. The last time I checked there are only 2 approved products: Chevron Techron Concentrate and MB # A 000 989 25 45 12. If I were you, I'd try one of these first.

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.

earld

I was going to fix the CEL light last week but life got in the way . Tomorrow is the day. I was reading the DIY on how to do this and I have a question. What size are the torx screws ? Also the Nut holding the tube on the egr ?
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.

ohlord

but my way eliminates all the extra stuff you tossed in. Simple,if handy with a drill,a self taping bolt,some crc maf cleaner,and a piece of wire.

earld

Doesnt your method require removing the tube totally? Or did I read the wrong set of instructions?
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.

earld

Finally I get to work on the benz. tomorrow I will be cleaning out the EGR tube and valve if necessary and change the Radiator since its been leaking a while. Any words of advice/warning I need to be aware of? Also about how long will it take to do this ? 01 E430. 3-4 hours seem ok. Thanks