My 98 lexus gs 400 starts at 4000 rpm when i turn my cat on. After warming up the car and press the gas pedal to take off my car idles super high and the rpm needle shoots quickly up passing the 4 mark on my dashboard but the car does not move. It accelerates at 2 mpr. What would be causing this

 

I had a similar problem. My air intake hose was off on the engine side of the mass air flow and ran like crap. Check for any air leaks or vacuum leaks. My 2 cents.