2005 cobalt, shuts off while driving.diagnostics code read "emmisions" on 2005 Chevrolet Cobalt

put new catilyic conv.(April), coil pack(march), new sparkplugs(march), cleaned throttlebody(march) car ran good till june, still shutting off,no warning, while on freeway.Today, started vibrating hard, after tapping coil pack again restarted. checked motor mounts-not loose, engine came on and stayed on.

Asked by for the 2005 Chevrolet Cobalt
When you changed the coil pack, did you replace the Ignition Module? What were the actual Code numbers stored?