After check engine light on analysis probable causes indicated #1 missfire, EGR problems, car feels like out of power when step on gas, then it goes but missing here and there

the EGR valve is ECM controlled to maintain the correct exhaust gas analysis and cool the compression temperature by introducing burnt inert gas back into the combustion process to maintain that analysis
Ig you feel that there is a problem in that valve , have the fault codes read first

P0300 is a random missfire code. What exactly would you like to know about it??

clear the codes run engine and see what codes come back up egr valve that could just need a clean, ignition coil and module that could be just because of the egr valve, misfiring could be the spark plug or lead on number 3, check clean all spark plugs, check clean or replace the air filter and check for vacume leaks.

Check for sticking idle air control valve and stuck open EGR valve. Both are common causes for very rough engine operation due to fuel-air ratio being too far off. Also check for large vacuum leak such as from rubber hoses connecting PCV valve to intake. Feel around for squishy or oily rubber which would indicate a leaking hole in the rubber hoses.

The light means that your engine management system feels something is wrong. The next step is to pull the error codes from the computer and follow that indication. It is fairly major, in terms of importance, for the engine to have output limitations. (30 mph is not fast enough, I presume...)

Have the cars on board diagnostic system read. An autoparts store like Autozone will plug in and read the codes for free sometimes if you are at their store. Or just visit a trusted local garage and ask for a read. It only takes a few minutes to read the computer with a industry standard OBD2 code reader. I bought one on ebay for 35 bucks for myself.

If you have codes but no continuous "Check Engine" light showing on the dashboard you may have missfires related to certain controls/sensors slowly going bad on your engine. Or you could have something outright mechanically wrong with the car like a vacuum leak or a clogged EGR valve.

Also, is this coughing causing other driveability or fuel ecomony or power issues? That can also be indicative of what kind of problem you are looking at.

If this problem persists but is minor....eventually the computer will send you the check engine warning. Sometimes it takes 1000's and 1000's of missfires to get a check engine warning! That's because of tolerances built into the software the cars computer is using.

Good luck!

Your EGR valve appears to be leaking. The valve is most likly dirty or sticking causing the exhaust gasses to enter the intake manifold and causing the missfire. At highway speeds is when the exhaust gas is allowed in the engines intake system for combustion chamber cooling and emissions purposes.
I would suggest removing the EGR, cleaning the valve and have the valve checked.
Good luck.

might have a vacuum leak. 2005 c class 230 kompressors have issues with the engine vent hoses under the intake manifold deteriorating and coming completely apart. This will cause mixture adaptations to max out and can cause missfires. Usually it sets a check engine light when it gets bad enough. There is a factory recall to replace these hoses, so check with mbz to see if your car has an open recall

i had that problem once. when i got under half a tank of gas in the tank. What i did was i dumped one bottle of gas line deicer in the tank and i have never had it agian. you may have some water in the tank. from condasation or i have a stong feeling i got my water from the gas station. i was using the same station all the time. so i tryed another gas station and so far no more rough idleing which was caused by the water i think and i am getting better fuel milage to. i hope this helps.

have you tried changing your plugs and try cleaning your air filter because the jumping feeling sounds like it may be missfiring and this is what could cause this most of the time.