03 malibu shudder

My malibu has a shudder almost like a dead miss that happens after driving on highway for a while and then stopping and taking off. also it happens when car idles for a while. It feels like engine cuts out and dies and then restarts immediately. 3100 v6 43000 miles intake gaskets have already been replaced by dealer under warranty. Could this be fuel filter, spark plugs, wires or maybe electrical like in transmission