know you echoed yourself?
And that S500Sport
brought the thread back to life with his question,to which I replied with a more complete anwser,a current parts supplier at several hundred dollars less than the two year old post, a caveat about never touching a maf insert with anything but the proper spray and the reason on 10-29-08 he needs to do more than think it is a MAF issue before he throws money at it as a solution for what may very well be a completely different set of codes or code.
Everyone replying to two year old threads is not dense,some are just opening new concerns.And everyone replying to those new concerns is not as thick as you seem to think either
Thanks for pointing it out though

 

I first got a P0170 and P0173 about three months ago. I took it to a Benz tech who does work on the side and he cleaned the MAF sensor. Same codes resurfaced a week or so later. He then put another used sensor in and that gave code sometime later. I got tired of this code, Fuel Trim Malfunctio (Bank 2) and finally went to Ebay and bought a new MAF sensor. I had a very difficult time installing this new sensor, as the circular clip that goes around seemed a bit small and couldn't move it anymore to get it to click and secure sensor. I finally end up breaking this circular clip and just wire-tied it temporarily until able to get a new one. The car ran ok with no CEL for a week or so, the CEL came on again. This time (I have an OBII reader), I was frusrated to see newer codes along with old one as follows:
P0305-Cylinder 5 Misfire Detected
P0307-Cylinder 7 Misfire Detected
P0300-Random/Multiple Cylinder Misfire Detected
P0173-Fuel Trim Malfunction (Bank 2)
At this point, I suspect I really need to remove wire tie and get circular clip. It was about $10 from dealer. Trying to put it on is giving me same problem as before. I suspect something is up with my Ebay purchased sensor. I then gave up and took it to the Benz tech who was having the same problem clipping it down. I stressed to him that I'm not comfortable with the Ebay sensor and that the diameter of it might not be within factory spec; so far he said the sensor is ok. Tomorrow I plan to take the circular factory clip to dealer and have them put it around a new OEM sensor and see if it fits easily. However, I am not sure this may be the cause of latest codes. I'm hoping but very doubtful. I changed all spark plugs about 6 months ago along with putting in a new valve cover gasket. Engine idle is fine, atleast no detectable roughness. Don't know what else to try other than succumbing to dealer trip, service, and hefty bill...PLS HELP!!!

 

The 170-173 i know for sure is your mass air flow meter !!!

 

Had same codes before and was the MAF. Happen on multiple cars. So far, I have never been unsuccessfull at cleaning it. You just have to make sure you are cleaning it right and every part. Including that plate the air flows through. Good Luck