Mercedes Benz repair: Mercedes Benz, mass air flow sensors, air flow sensors

Question
I have a 1995 SL 600 up until a month ago it was running great. If a push the accelerator to the floor it sputters bogs down and backfires...If I slowly depress the accelerator it gains speed ok...I took to a susposedly Mercedes Benz mechanic and $600 dollars later the car still does the same thing and he can't figure out what it is, he changed spark plugs filter etc...

Answer
First off, if you have already had it to a mechanic and paid money for a repair that did not fix the problem, then you should return the vehicle and the mechanic should correct the problem and you should owe NOTHING for the remaining repairs required. Spark plugs, wires, and filters do not cause problems like that unless the majority of the plugs were inoperative. There are a few things that could cause that problem such as throttle position sensors, mass air flow sensors, I have even seen O2 sensors cause similar problems. Hard to diagnose online.
I would return it to the mechanic or take it to a MB dealership and send the mechanic the bill for the faulty diagnosis and repair.

Let me know what happens and I hope you can get the mechanic to correct his mistake. If he does....remember you should owe NOTHING more as it should have been diagnosed correctly the first time. The mechanic should also verify his repair before returning the vehicle to you.