i had only one problem with my car cherry qq. (engine light)
its on petrol.cherry mechaincs charged me 300 rs for reparing sensor. however after driving it for 4000 km i have found that its because of poor quality of fuel(petrol). idsi and mpfi gives better fuel millage but require better fuel quality. my car requires 93 octane level(its written on fuel lid). petrol sold at pso, shell or any other is less than 92. at lower rpm it does not effect fuel management but at higher rpms it effects.
to solve the problem i used to shift to lower gear and rpm and then again shift to higher gear and raise rpm. after some time it dispaered. as soon as it disappeared i slowed down the car.
however if i fill high octane then no matter what rpm is ,enine light does not apear. but no body can drive on high octane so i have found a more economical solution .
i have found caltex petrol with tetrocan better suited to my car. its certainly not as good as high octane but it sure solves the engine light problem, please check it and reply. i haven't driven my car on motroway so don't know what happens at 130+ speed.