Hello all, I'm trying to figure out this problem in my c200 2012. It all started one month ago when I began to feel lost in power when approaching a stop right before a completely stopping. When I took to it the mechanic he scanned it for errors and it was showing the code P233622 (knocks limit in cylinder 1 were exceeded). Then another code popped out (Fuel pressure is too high).
we noticed also these symptoms:
Sometimes is cold starts, the car vibrates as if it is going to shut off, after hitting the gas pedal the vibration will go away.
The engine oil smells like a strong fuel smell.
Exhaust smoke smells fuel as well.
Fuel mileage is very bad.
The spark plugs heads are black, noting that they were replaced a month ago.
so he told me that my car is giving rich mix which means that its taking fuel more than it should be.

Please tell me what I'm dealing with here as the mechanic told me to replace the rail fuel pressure sensor and change oil with filter.

Thanks.

One more question, is it ok to fix a used fuel sensor from eBay?

Fuel pressure regulator is bad, causing to much fuel injections, or bad injectors.

Hi,
my 2012 c300 have the similar problems. I can feel my car slow rapidly after i released the gas paddle and i was not using the brake.
I believe we have the same felling like you said: "feel lost in power when approaching a stop right before a completely stopping."

So dose your mechanic said this is caused by fuel pressure?

Have you changed the sensor yet? If so then please explain what's the condition now. I am having similar issue on E250 CGI.
Thanks

Thanks.. then I am not going to replace it.