On the FM band the radio seems to to go in and out of tuning the little st in the display for stereo goes on and of as you drive its like ive got a week signal. It used be fine , as I am in Melbourne it should cristal clear.Any ideas.The radio is after market sony in a EF!

check that your antenna cable is connected properly at the back of your head unit, and also behind the left kick panel (above the ECU).