Yaris 2001 The engine yellow/orange warning light in the dashboard

[cabbage2001]

Thanks Guys, for you help. Is it hard to clean the injectors or will i have to take it to a mechanic. Also would i be able to change the Petrol Filter and if so where is it. Was told it under the back seat? or would i have to get a Mechanic to do that do just dont want to spend big $$$£$£$$££$ for someone doing it

thanks Colin