P0400- Egr

[lesgawlik]

'95 C220

After clearing codes and thinking I was done for a while, the CEL came on. I pulled a P0400 code.

I searched this site and benzworld, and the links about checking and cleaning the EGR tube don't work.

On the 4 cylinder, how hard is the EGR tube to get to? I assume it is a tube connecting the exhaust manifold to the intake manifold.

I heard there is an updated tube. Does this apply to the C220?

Any help/pictures/links would be appreciated.

[jnenad16]

yeah, that tube gets plugged up with carbon, and the restricts the flow of recirculating gases. you can either clean it or replace it. it runs from the EGR which sits on top of your exhaust manifold and goes around the engine block into the intake manifold, just below the throttle body.

nenad

[lesgawlik]

Is the tube metal (I assume it is)?

Is there an update which is worthwhile installing?

Is the tube routed from passenger side behind the engine to the driver side near the throttle body?

Thanks

[jnenad16]

the tube is metal. to date, I still havent replaced a single of those, I just clean and reinstall them, I never had any comebacks with the same problem. so I dont know if the new one is an updated part or if the dealer just wants you to buy a new piece.
yes, that is how the pipe is routed. on inline 6's its a bitch to take off, but it should be much easier on inline 4's.

nenad

[ncd]

Originally posted by jnenad16
the tube is metal. to date, I still havent replaced a single of those, I just clean and reinstall them, I never had any comebacks with the same problem. so I dont know if the new one is an updated part or if the dealer just wants you to buy a new piece.
yes, that is how the pipe is routed. on inline 6's its a bitch to take off, but it should be much easier on inline 4's.

nenad

worth doing @ 100K+ then? as some additional maintainace...
am i corecting in believing the benifit is.. you should get better gas miles for getting exhaust gas out quicker/more efficiently..

[jnenad16]

the only major impact this tube has is on the emissions, so if you have emissions testing in your area, you better get it fixed. also, you might see a bit higher fuel comsumption because your car will be running richer now.

nenad

[ncd]

ah ok the exact opposite of what i was thinking then

[KenzBenz]

and how do you clean this??

[jnenad16]

if the pipe is completely plugged up, the only way to clean is to remove it and snake it. if the pipe is lightly clogged, what I do on my car is I disconnect it on the EGR side and put a rag under the throttle butterfly(which is where the pipe connects to on the intake side) and I shoot a can or two of carb cleaner through the EGR side opening, and all the carbon and oily gunk get trapped on the rag. I do this once a year as a preventative maintenance.

nenad

[Proven Guilty]

I've done the exact maintenance over the past weekend. the EGR tube was so plugged up I had to remove it and soak it in a small container of kerosene overnight. I also pulled the EGR valve off, and checked the rubber hoses. The breather hose was torn, and possibly causing a vacuum leak (not sure if its essential to maintain vacuum preassure) so i'm going to replace that as well.

After cleaning out the EGR tube, and cleaning the EGR valve as best I could, it idles MUCH MUCH more smoothly. I'm going to replace the EGR, and the other valve right near it since they were so filthy and such inside as well. It couldn't hurt, and i'm still pulling PO400 from like 6 months ago with check engine light on. It's just a process of elimination for me.. Next after these 3 parts replaced will be oxygen sensors. They're due based on mileage with past experiences.

[Proven Guilty]

Originally posted by jnenad16
if the pipe is completely plugged up, the only way to clean is to remove it and snake it. if the pipe is lightly clogged, what I do on my car is I disconnect it on the EGR side and put a rag under the throttle butterfly(which is where the pipe connects to on the intake side) and I shoot a can or two of carb cleaner through the EGR side opening, and all the carbon and oily gunk get trapped on the rag. I do this once a year as a preventative maintenance.

nenad

Hmm, the tube on my C230K was very short. I expected it to go to the opposite side under the throttle body too, but it plugged right into the side of the block under the exhaust manifold.

The EGR valve actually threads onto the tube on my car. Perhaps there's another tube I could clean more gunk out of?

[jnenad16]

Originally posted by Proven Guilty
Hmm, the tube on my C230K was very short. I expected it to go to the opposite side under the throttle body too, but it plugged right into the side of the block under the exhaust manifold.

The EGR valve actually threads onto the tube on my car. Perhaps there's another tube I could clean more gunk out of?

thats because your C230K doesnt have an air pump, which on non-komp models blows air into the crankcase through a check-valve.
I dont know for sure if this tube exists on your car, I dont recall ever doing this to a komp model.

nenad

[xvvvz]

PG - Please let us know how you do with this and please post any pics if you take them. This is something I want to check and it would be great if you can share any tips you learn.

Thanks.

[ncd]

Select * from metal_tubes where tube = connected to egr

[lesgawlik]

I had a problem that was largely fixed when I replaced the spark plugs. The car went into limp home mode after heavy acceleration. That would clear after I started the car.

Now, it goes into limp home mode after I decelerate, like after making a sharp turn. It's setting a P0400 code, but I'm not sure I believe it, since I know I've got a bad wiring harness. It consistently sets P0400 codes.

From these posts, it seems that the EGR really affects only emissions. Are there any drivability problems associated with the EGR? Car is C220.