CLK55 mass air flow sensor

Take it to dealer to get proper diagnosis. You may have transmission problem... which may be caused by a faulty sensor.

I don't want to go to a dealer if I can avoid it. You said in your reply to my other post, that the dealer diagnostic tools were fairly similar to Carsoft et al. So what extra could a dealer do?

What sort of sensors are you referring to? Would Carsoft pick up errors with transmission sensors?

Do you have good understanding of mechanical and electronics for cars? I need to know in order to gauge if Carsoft, Star or OBD2 scanner would be of any use...

Just because the computer spits out O2 trouble code does not means the O2 sensor is dead. It only merely tells you the reading is out of its range as programmed. You have to get to the right function to check every O2 sensors to see if it is working... then determine if it is the MAF is bad rather than O2.

I have bought the $140 Carsoft kit sold on ebay. It comes with hacked old version of Carsoft and zero instruction on how to use the software. Even I am stumped trying to use it and I am very computer literate.

On the other hand, you can purchase a high quality OBD2 scanner that will read alot of computers in the car. There is another scanner strictly built for Mercedes... and I think the name is Trina something... that cost about $500... which I am saving up for... no need to buy it until you need it as the software update for the scanner is just as expensive.