Maybe a clogged catalytic converter.
This is a small drum like thing attached with the exhaust pipe beneath car.
more than 90% of these tiny cars has issues of Cat. converters blockage. and in most of the cases the things came back to normal after cleaning it well.
there are many workshops who do it and charge minimum amount of money. Visit your nearest workshop and ask them Catalytic Converter Service Kernay Kay Kitnay Paisay Letay Ho. And they will share the cost.
which city you are from ?
