hi!
I need help with my Honda Civic'99 Vtec VTI automatic. the check engine light goes on for a while then will go off, kinda weird coz if I start the engine with this CE light on the sound of the engine's rev is not so good (parang palyado) BUT if I wait 5 secs tops CE light will die and the Engine's rev is normal.

Engine is running fine, no notable engine noise, smooth running.

could this be loose wirings? grounded wirings?

Tnx!