Hello all,
I bought Ml 320 W163 4 Months the ago, engine performance is very low so I have done

- injector cleaning
-MAF cleaning
-air flow cleaning
-plug changing
-fuel pump change
-plug change (using Bosch platinum plus)

Following is the current OBD2 code, mechanic are saying all sorts of thing, Pls advice which area I should troubleshoot

 

I would address the cylinder misfire first as that could be the most serious of the issues. I've also attached a DIY on the O2 sensor replacement.

Mercedes-Benz W203 Oxygen Sensor Replacement - (2003-2005) C320 | Pelican Parts DIY Maintenance Article