A bit of a sore subject right now , my Vios is about a 2006 model , the yellow light came on a couple of days ago , you know the one , little yellow engine warning. The independent mechanic that always looks after the car could find nothing wrong , he plugged in his computer gubbinz could find no fault , took it round the block and said car is ok. Today in about an hour we are going to Chiang Rai in it , 'er indoors is very worried of course as they always do.