phoung

My car is throwing a 0400 code, EGR circulation. According to the forums, it may be my EGR pipe. I removed the valve and pipe and the pipe looks great. Not much carbon buildup at all. I can easily blow straight though it. Does anyone know what else can throw the code?

DanielFD

this was being discussed on this thread:


https://mbworld.org/forums/clk-class...r-removal.html


I'm having the same problem. I thought I had repaired it when I found vacuum lines that were severed. but now its back after 2 months.

Airton123

Try to order mercedes egr emulator from this: http://www.ces24.com/
Before ordering, know what your egr is electrical or vacuum?

cstevenson

I've got the same problem, accompanied by a throbbing at idle. I wound up disconnecting the vacuum line and I'm living with CEL for now. I also cleaned it up good, I'm wondering if it's a vacuum leak somewhere.

Airton123

Cleaning is worth for time, it is mechanical malfunction.

JEBAtlanta

This past weekend, I changed the spark plugs on my CLK320. I also thought, while I had the ignition packs off, I'd see about cleaning out the EGR tube - to see if that fixed my P0400 error code. I also note that there are plenty of recommendations to check the vacuum hoses.
First, I am not really sure how many vacuum hoses I need to be checking or where they may be, but I'll trace back from the EGR valve and figure that out. However, when doing a visual inspection, I noted that the rear breather hose connection on the right side was no longer attached to the breather box. I have no idea how that happened, but there does not seem to be any alternative to replacing the valve cover. My immediate question is whether the breather hose being "disconnected" would have any effect on the EGR system and, therefore, throw the P0400 code. If that condition is going to throw that code regardless of what other troubleshooting I do regarding the EGR valve, tube or vacuum lines, then I'll have to defer that troubleshooting until the new valve cover arrives.

Many thanks in advance.



Left Valve Cover - Broken breather hose connection on the right