Novak 6.5T motor problem

[superek4]

Hi, I think I have a problem with the sensor wires or sensors in my motor. Tried reseting the GTB n change the motor the esc works fine.

The 6.5 motor when throttle the car goes slow n fast without me throttle harder n it happens all the time.

Sending back to novak is it worth it? I am from Singapore.what went wrong?