Hello, I have a 2000 S500 that when I turn the key the car starts fine but then revs to approximately 4000RPM where it seems to pulsate (I have read that that is a safety feature to prevent over revving). I have replaced the MAF sensor on the advice of others but the engine still races. Do I need to reset something? If I attempt to drive the car, it just continues to accelerate until I turn the car off. (NOT A GOOD IDEA) Simply put, it's as if someone is flooring the accelerator. The check engine light was on, but no longer. I obviously can't drive the car to have it checked. Any Ideas?