Just picked this cabrio up with 47000 miles. This is my first Merc. Car has all its service records and is extremely clean and well cared for. If I push the pedal down, even slightly aggressively, the throttle will stop responding for about 3-4 seconds. Turn the car off and it seems to reset back to normal. Push pedal, repeat ....

Any ideas? Throttlebody? I appreciate all input.