Rhettvette

Hi, When I start up runs smooth for a few seconds then runs rough
engine light blinks. Anyone have a idea what's going on before the
dealer beats me up.

madrob2020

When CEL is flashing it means a malfunction has been detected. Get to safe place to park, turn off engine for 10 secs. at least & restart. If light is still flashing reduce engine speed, avoid hard acceleration, uphill grades & see dealer ASAP because emission control systems (or worse) could be damaged. This is per OM.

owc6

Frankly, I would not even drive with a flashing CEL.

Have it flat bedded to the dealer if still flashing; that usually indicates something major which may very well get worse if you drive it.