My vehicle is a MY2000 ML320.

Does this situation sound familiar in anyone's experience? Any ideas would be greatly appreciated.

!. Coming to a stop, groaning sound (like the ABS pump?) with flashing
yellow triangle. No other of the warning lights in the lower instruments
come on.
2. Onpressing the accelerator. the triangle flashes and the engine bogs
down a second, then accelerates and the triangle goes out. No other
indicator lights.

If you have any thoughts, please send them along.