Drove home tonight, the check engine light came on startup. Got home, shut off, started up, light still on. Gauges look good, everything works. Shut off, cycle key 3 times to see if it will display a code(being a 99 wasn't sure if it would, this was my first chance to check) nothing, no code. Started it again, no check engine light! Could I have been able to reset the light even without being able to display a code?