1976 Mazdas with EGR are equipped with a maintenance warming light on the instrument panel, which lights every 12,500 miles. The light indicates that the EGR system should be checked for proper operation, using the procedures outlined. The EGR valve should be removed and cleaned every 25,000 miles.
The switch controlling the light is installed behind the speedometer. To reset the switch after the maintenance has been performed, remove the cover from the switch, and move the switch knob to the opposite position.