A common problem with Toyota vehicles is the owner may find the “VSC OFF” and “Check Engine” lights illuminated simultaneously. VSC stands for “Vehicle Stability Control“. It is likely that “Traction Control” will not work while this light is illuminated. On some vehicles, the “skidding vehicle” or “TRAC OFF” light may also be lit.
Most Toyota owners will find that when the Check Engine and VSC lights are lit, there is a problem with an O2 Sensor or gas cap. Try tightening or replacing the gas cap for a hopefully cheap fix.
To be sure of the problem you may want to take your vehicle to an Auto Zone or NAPA store to have them plug in a code reader to determine the problem. Another option would be to take the vehicle in for service.
If your problem turns out to be O2 sensor related, you can continue driving the vehicle without problems, but you may not achieve appropriate gas mileage.
O2 sensors can be difficult or easy to replace yourself depending on the vehicle. Some require access under the vehicle, while others are accessible under the hood.