Code 0306 2007 Mercedes E350 4 Matic
New Coils
Spark Plugs
ECM repaired
Fuel injectors 4 & 6 replaced
What is it that I may be over looking ? Still getting P0306 code on 2007 Mercedes E350 4 Matic
When I drive the car and runs smooth until I sit at a light and it idles , thats when it idles rough again
Last edited by RLN; May 8, 2018 at 01:00 PM.
Last edited by RLN; May 8, 2018 at 12:58 PM.
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I have had a bad an catalytic convertor and it would have turn the exhaust manifold cherry red and the car over heat but i'm not having that problem with this car.

This mentions a bunch of other possiblities:
https://www.autocodes.com/p0306_mercedes-benz.html
As for the converter, I'd replace the two upstream O2 sensors if you're going to replace anything, but it doesn't look like you have any codes to indicate it's bad. The O2 sensors aren't that cheap though, even the cheap ones on rockauto are over $50 and the Bosch ones are about $100 each. Shouldn't be that bad to replace, probably just an access issue getting at it with the O2 socket.
I read where I could turn the steering wheel hard left then hard right and that might help so I did it . Anyone have the ESP problem along with. Misfire?
I looking at other vehicles and Benz is slowing coming off my list
Last edited by RLN; Jul 14, 2018 at 04:39 PM.

Your ESP problem could be something else entirely. You should get yourself a good scanner that can do MB codes. That might figure out your ESP problem. That could give you a code that will tell you if you have a bad brake switch, steering angle sensor, wheel speed sensor, or bad yaw sensor. When ESP goes out, the cruise control goes out with it.
The W211 seems to have more mechanical problems than the W212, over in that forum things seem to be better. I think 2007 still had some minor issues left from the face lift, 2008 and 2009 models seem better but of course all of them have issues with the intake manifold.


