My 1991 Peugeot 405 has recently been displaying the STOP and warning lights intermittently on the dashboard. This only happens after I do long distance driving, but have to slow down e.g. a slower car ahead. As soon as I put my foot on the brakes, the light begins to flash intermittently. If I am operating the ventilation it's a bit more. Any electrical gadget that I add (headlights or wipers) or is added automatically (like radiator fan) increases the flashing. The engine doesn't show any tendency to go off though. As soon as I rev the engine to start moving again the flashing stops. My plugs seem okay because I experience no jerking when I drive. This does not happen during town driving. From all I've observed, it seems to be a power issue. Can this be a leaky plug wire or a faulty distributor rotor?