Same problem here, c24 with sr20de engine and cvt transmission. Observation: 1. The car start and drive well for first few mins or km defending on road and traffic condition. 2. After less than an hour, the car start acting weird over rev while cruising then malfunction, need to stop and wait for atlest 10 mins to cool down. 3. High acceleration on 20kph 4. Sportsmode flashing 16x 5. After sitting for 10-30 mins car drive well and start acting again after awhile. - i replaced the stepper motor, still problem persist. - replaced the valve body same problem occur. - asked several so called AT specialist and insist to replace the transmission. So i got 1 Standard 5speed AT from local serena not cvt. But was not installed. 6. One time Its raining when i was driving and realized that i didnt encounter the same problem. After searching and observation i realized that the transmission is overheating. So i installed 2 external cooler to cool down the transmission fluid. I took it for a test drive for about 180km mix road and traffic condition and never encountered the same problem. Next project is to bypass the radiatr. DIY cooler with watercooling like the radiator except it doesnt heat up like a radiator. Hope this helps.