yah....tats the thing la....the butterfly which open n close 1 when u press n release the pedal....it can apply for all injection car.....but mostly wira gives trouble like tis la because of the stupid ECU....must always keep the butterfly n the area around it to be clean so tat rpm stable.....must make sure the ring there is smooth when u rub.....cuz even abit dirt oso will affect 1....