How do you know when a egi relay is bad?

You can determine if an EGI (Electronic Gas Ignition) relay is bad by checking for symptoms such as the engine not starting or stalling, poor fuel efficiency, or difficulty in maintaining idle. Additionally, using a multimeter to test for continuity and voltage at the relay can help identify issues. If the relay does not pass these tests or shows signs of physical damage, it likely needs replacement. Always consult the vehicle's manual for specific diagnostic procedures.