Ok, after a few weeks of CEL coming on, and pulling the same codes, 170 173, I reset the CEL, drove 75 highway miles today and no problem until I slowed to the first light and noticed when the tach dropped to 500 rpm, the light came on.
Seems when in drive/gear and coming to a stop, this is the only time the CEL hits. It runs fine otherwise, good power, good milage etc. Reset the codes, drove back 75 miles and as long as I never let the tach bounce to 500rpm and back up, it was fine. When I slowed down and was pulling into my shop, idle dropped, just that little dip, and CEL hit again at this low rpm mark. It doesn't shudder or stall, just when it drops fast, it sends the CEL. Is this the MAF, or what would cause this? I can see if it idled bad, erratic acceleration etc, but is this a MAF acting up?

 

Code P0170, P0173 is the adaption values out of range. As long as you dont have any vacuum leaks than 99% sure you have a bad Mass Air Meter. Very common

 

Thanks ML God. I checked all connections and nothing leaking anywhere. Will see what I can find for a MAF tomorrow. I see it's the same MAF on many Mercedes car models in 1998 to 2003, so should have a chance finding one easy.

 

Here it is... So expensive but easy to change. Mas Air Flow Sensor A little cheaper here MAS