[BolivianFuego]

Have to get my damn emissions done on the old C280 (99).

I love this car but this code has plagued me for a while.

From what I read, common sense tells me rough idle = EGR but like my car is now, runs smooth but still has the p0400 it's probably the Changeover valve? No??

Thoughts?

And if Changeover, how hard is that to change? Thanks in advance!

 

[khomer2]

Have to get my damn emissions done on the old C280 (99).

I love this car but this code has plagued me for a while.

From what I read, common sense tells me rough idle = EGR but like my car is now, runs smooth but still has the p0400 it's probably the Changeover valve? No??

Thoughts?

And if Changeover, how hard is that to change? Thanks in advance!

You've read this?

C280-Rough Idle, Lacking Power to Accelerate, P0400

As the title suggests, I have a P0400 (along with two or three specific cylinder misfire codes) which is giving me a surging, rough idle and a lack of power at low RPMs. I replaced the plugs, cleaned the MAF and EGR valve and snaked the metal pipe to the rear of the engine, although this was...

www.benzworld.org

Scan and erase codes. see if the code comes up again.
Do the simple stuff first..
Have you cleaned the EGR?

 

[BolivianFuego]

Did all of that some months back.
Even Changed the spark plugs earlier last week. This damn code...outside of the code, after changing the spark plugs, the car runs like a dream.

For me it's either the EGR or the changeover valve.

 

[MB-W202]

EGR pipes may be clogged with soot.