2000 MR2 Spyder

chances are your car is in a clean run mode. your computer thinks that your polluting and not meeting emissions so it cuts back the fuel trim. This could be because of poorly installed aftermarket parts (turbo, injectors, ECU etc) a bad post cat O2 sensor, a bad cat (or missing). depending on your mileage and year it may also be a warped timing belt or a malfunction in the cam variable lift mechanism.

its called pre-cats, start looking for a new engine and GUT THE PRECATS! join Spyderchat.com and read a lot :)

I might have a clue and its worht looking at, no boddy usually thinks of it: Try unscrewing your camshaft timing oil control valve, its held by 1 bolt and is situatet just above the alternator in the engine block, might be faulty or even plain cracked. By Toyota this is called a ocv valve an is activated by a solenoid. Hope this is helpful.

2 things come to mind. Clogged cat, a vacuum test while reving to that rpm should tell. Or a bad TPS. No it's not a MR-2 but I had a celica that when the TPS failed it never left idle mode and created a low "rev limit" becasue it never gave the car any extra fuel.