2003 6 cylinder Impala running rough

Hi. Hope some cascasn help. I have a 2003 Impala that was my moms..She passed aweay.The car has been started but not used much..Maybe 10 miles a day..It has been running beautifully.This morning I noticed it was a bit hard to start...Shortly there after it started idleing rough..I did make it home..When I came to a stop light I would put it in neutral a d give it a little gas..Any ideas of where I cascasn start to look?..That is for any and all help..Pete

This is now a 14 year old car but also likely low miles. I suspect it still has the original Ignition wires with insulation breaking down.

With the engine running, area lights off in the dark look for Ignition wires spark arcing to ground. You can also spray a mist of windex window cleaner in the area of the spark plugs. any arcing seen replace the wires and spark plug.

If the engine is a 3.4L pay close attention to the #1 plug wire boot .

Which V-6 is it? Buick 90° or Chevrolet 60°?

If the ignition system is determined to be intact, test fuel pressure both KOEO and while running.