I have a 2000 Proton Waja MT which was running fine until recently when idling speed of the engine came down to less than 500 rpm after the engine had warn up. Normally it's around 750rpm. What is wrong with this car?
Have you send the car in to be checked? It could be faulty idle valve or even misfiring plug. The best is to let the people with the right test equipment check it out.