i know its an old thread, but on my 36 amg M104 i have the same flat spot at 3400 and then its fine at abt 3700 rpm.
I have changed the resonance flap, its relay (is that the OVP) and have changed the electronic throttle along with full service.

so what is the ovp and how can it affect the faltsopt?

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Jay,
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-1995 Blue W202 C36 AMG (M) SOLD ;(
-1995 Black W140 S500 (Lady)
-1992 Black W124 E300 (Dima) (Ex-Mosselman
Twin turbo Kit).
-1988 Black W124 300 E 4-Matic.(Nadeen)
-1983 Brown W126 500SEL.(Old Lady)(Sold)
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