92 Legacy Check Engine Light??

[coldsteelcrown.com]

The light does not come on, nor stay on all the time.

When I first start her up in the morning or if she sits for a few hours after driving the light does not come on?

But when I drive to the store lets say, shut her off and restart, the light comes on????

Runs and drives the same when the light is on.

Any suggestions????

Thanks much

John