I have a 2008 Honda fit with 76,000 miles. When the engine is cold, the blue indicator light is on. If I let me car idle for too long, the check engine light turns on. The car only has to idle for 30 seconds before the check engine light turns on. It usually goes away in a few days, but yesterday it started to blink for a few seconds and I turned off the car thinking it was just because of the cold. Then this morning the light was still on and after 5 minutes of driving the car it started to blink for 10 seconds then stopped. Do you know why this would happen? It seems to only do this when the engine is cold. Thanks.

 

Blinking CEL means misfire that could damage catalytic converter.
Do you note any roughness or jerking when idling?
Pull out the code and post it here
Need to know also if valves were adjusted or ignition coils (and/or spark plugs were changed)