the EX warning light is existing only in cars exported to Japan. It indicates that the catalytic converter is hot and the car should not be placed on dry grass or over inflammable material. If you drive the car at high performance, the light will appear always.
If you run nervous by this unneeded warning, just remove the bulb, or you may try to insulate Pin No. 5 at the Relais G16. Removing the relais is not working as buechse007 told me.