That is a non manufacturer specific generic code I believe, so may be wise to scan with a professional tool, but could be due to the PCM control module seeing a difference between the throttle body butterfly and the actual throttle pedal position, possible carbon build up on the throttle body (unlikely if that age and not high mileage), or one of those parts being faulty!? Might be possible to carry out a throttle body reset/relearn basic setting procedure to the throttle body, but it is possible (although rare) to make things worse doing this if the butterfly has heavy carbon deposits. Could also simply be caused by a dirty or faulty MAP sensor, may be worth removing the map sensor and checking if it’s clean.
